Back in WoW, small group instances used to be one of my favourite pastimes in the game for years - until the dungeon finder slowly sucked the fun out of them for me, that is. Unsurprisingly, SWTOR's more old-fashioned flashpoints make me very happy, and I've run all of them up to my current level at least once, some of them multiple times. It's been an interesting ride so far.
Difficulty-wise they seem to hit a pretty sweet spot for me. Trash is mostly very easy, but there are patrols to watch out for, mobs of different strengths to consider, and sometimes enemies surprise you by entering the scene unexpectedly. Personally I feel that this creates a nice atmosphere where most of the dungeon is fairly laid back, but not mindlessly boring, as you still have to watch where you're going and what you're pulling. The bosses tend to be a bit harder, and I've had quite a few deaths and even wipes at the hands of some of them. They all have a couple of mechanics each that you have to pay attention to and that can't be safely ignored, but there is some margin for error so the fights don't exactly feel twitchy either.
Interestingly enough, I've already had two runs where our group failed to complete the flashpoint because we simply couldn't get past a certain encounter. This felt a bit strange and surprising to me initially, as I haven't experienced anything like it since my party found it impossible to kill the last boss in Grim Batol when we ran our very first heroic five-man after WoW's Cataclysm launch. In SWOTR, the two offenders that had us running into a brick wall were Athiss and Taral V. On Athiss, we just couldn't get past what was I believe the last trash pull before the final boss, which contained two elites that both had AoE attacks and were wearing our group down faster than I could heal it up again. Since we were on the lower end of the level range for the place, nobody in the party had their long-duration crowd control abilities yet either. On Taral V, we first died a few times to the bonus boss before giving up on him, and then failed to kill the last boss too as he wiped us out within seconds every time he hit his low-health enrage (which was promptly patched out two days later, which is telling). In both cases we came back with another level or two under our belts and completed the whole thing easily. At the end of the day, the initial failure wasn't actually that terrible, as it just spurred us on to come back and get revenge together, not to mention that it provided some unforgettable memories to bond over.
Another thing that I found noteworthy was that most flashpoints seem to reward both explorers as well as people who've honed their crew skills. The former was particularly evident for me on Taral V, where the way through the instance is fairly straightforward, but there are plenty of hidden nooks and platforms that contain bonus objectives and chests. Both times I've been in there, our group had fun clearing out as much of the place as we could, and one time we even found a purple item in a chest. The runs took a lot longer than strictly necessary, but the whole experience felt very rewarding and fun.
As far as crew skills go, there seem to be a lot of little bits and pieces in many flashpoints that provide you with small bonuses if you take the time to notice them. On Athiss for example you can go into a side room and use scavenging to repair a broken droid, which will then follow you around and act as a combat pet for a bit. On Hammer Station, you can use crew skills to drill a hole through a wall to create a shortcut to the first boss. None of it is even remotely necessary, but it's a little something that feels fun. I was reminded of how I used to be grateful for someone who could pick locks in WoW's Shattered Halls so that we didn't have to go through the local sewer to get to the first boss. Sometimes it's the little things that make all the difference.
Finally, I found it notable that there's a huge stylistic difference between flashpoints. The first one you get access to on either side (The Esseles / The Black Talon) feels very creative and exciting. Lots of moving around, multiple conversations with NPCs, multiple light/dark side decisions that really make you feel like you're influencing the story. I found it to be quite different from what I usually expect to find inside an instance, but in a good way.
However, after that the next couple of flashpoints honestly felt like a bit of a disappointment. Hammer Station, Athiss, Mandalorian Raiders, Cademimu... there's nothing wrong with them, but they don't utilise SWTOR's unique selling points nearly as well and feel a lot more like classic dungeon crawls. Yes, there is a bit of voice work, and at some point there's usually a light/dark side choice for you to make, but it tends to feel a bit tacked on. Hey, there's a room full of innocents over there, want to save them or kill them? At their heart, these four instances can easily be summed up as "go kill some bad guys and then kill their boss", detailed story be damned. Still, this is only a problem when you compare it to what came before. Truth be told, I'm perfectly happy to do a classic dungeon crawl with some friends. I mentioned our fun little adventures in Cademimu before.
Interestingly, just as I was going to accept that the Esseles and the Black Talon were obviously outliers, the game threw Taral V and the Maelstrom Prison at me, two separate flashpoints that are part of one continuous story. They are not quite as interactive as the Esseles, but the story is considerably more involved, and at the end of the Maelstrom Prison we were rewarded with a hugely satisfying boss fight and a massive lore revelation (which might not actually mean much to Republic players without much prior knowledge, but fortunately for me I had just played through Dromund Kaas on Empire side, which had conveniently provided me with some context for events).
At first I was a bit bewildered by the way some flashpoints are so story-heavy while others aren't, but after doing some research on it, I think I understand the reasons for it. Basically, the difference seems to come down to whether a flashpoint is faction-specific or the same for both sides. I remember listening to a developer interview where the guy confessed that originally, they had intended to make all content shared between the factions to save development time, but the resulting stories were pretty dumb because you can't really make a very compelling quest that both Luke Skywalker and Darth Vader would find equally engaging (as the dev put it). So maybe those flashpoints are leftovers from early development, or the developers simply decided that they could afford to have at least a couple of group instances with a comparatively weak story, especially considering that they would be repeatable content at endgame, at which point the story fades into the background anyway.
All in all, I've enjoyed myself enough that I'm definitely looking forward to exploring the flashpoints that I haven't seen yet, and so far there hasn't been one that I wouldn't be happy to rerun.