Personal experience will vary of course, but I'll give it a shot.
Not sure I understand what you mean by balanced here. If you mean like the raid boss difficulty ramps up as you progress instead of the first boss being the toughest, then I'd say that Explosive Conflicts (new OP) is like that as opposed to Karagga's Palace, where the first boss is a lot more challenging on Nightmare than the last. If you mean class balance performance wise, from my raid's parses things are on equal footing for the most part, with the exception of possibly the Sniper who usually parses lower than the rest of us. Whether this is a class/spec or player issue, I'm not sure as yet.
Depends on your server. Some guilds worldwide cleared the 16-person Hard mode of the new OP the day after it was released and some guilds have yet to kill a boss. There is a Nightmare version of the OP still in the making, so we'll see how things are when that hits.
I used to raid endgame content on both WoW and ToR for some time, only recently stopped on WoW because I just had more fun on ToR. So yes, I find it enjoyable.
WoW's had seven years to build it's endgame content, and it shows. If you come into ToR engame right now expecting fight mechanics to be as complex (for lack of a better word) as WoW, then you'd likely be disappointed. Give them a chance though, EC's more complex than EV and KP, so they're getting better pretty quick. The fact that they don't have to build fights that assume the player's using a boss mod will help in the long run as well, in my opinion.
I love it, but choose your server carefully as that single decision can make or break your experience.
From my experience (10/10 nmm EV/KP, 2/4 hm EC) it's pretty good.
Is it balanced but challenging?
Yes. There are a variety of mechanics that challenge the tanks, healers, and dps both individually and in coordination. There are even a couple of "puzzle" bosses where several raid members are doing something besides hitting the boss to complete the encounter. Between the first and second tiers there's around the same mechanical diversity as Firelands but it's not as polished or complex.
As far as class balance, all dps specs are very close in dps. Not like WoW where only half of the damage specs are even remotely viable in PvE. Melee are a little lower, but ranged lose a fair amount of time on target from having to move, so it all works out pretty even. My ops group started using a new external meter called MOX Desktop Raid Meters, and we were all very close in dps and damage done.
How competitive is it?
The server that I play on there are 4 progression guilds, and we all have friendly rivalries with each other. To my knowledge there's nowhere near the competitiveness of WoW, but that will probably change in the future if more sponsored guilds start playing.
Is it enjoyable?
If you like Patchwerk style fights then no. If you like mechanically diverse fights with just a little room for error then yes.
Do you think it will be able to stand up to wow's endgame progression (when it was good)?
IMO yes it will definitely be able to stand up to progression back in Vanilla/BC, and the difference in difficulty between T1 and T2 is about the same as between Kara and SSC/TK.
Bioware needs to refine their product quite a bit, but that'll come in time. Right now SWTOR is far more enjoyable compared to WoW's current content. Overall it feels like Burning Crusade did, but a little more forgiving, and without addons.
I'm considering purchasing SWTOR but I wanted to get some input first about the endgame content.
1. Is it balanced but challenging?
2. How competitive is it?
3. Is it enjoyable?
4. Do you think it will be able to stand up to wow's endgame progression (when it was good)?
5. Overall thoughts?
1. I think Bioware is on a pretty steep learning curve with raid content. Regarding Balance/ Challenge, very limited rezz possibilities during a boss fight stands for challenging content where each and everyone has to play their part. There is at the moment only one encounter which I really don't like due it's randomness (bonecrusher).
2. It's less competitive than for example EQ2, everything seems more relaxed on my server. I'm waiting for Denova NM to actually see some competition since HC was on test for "ages".
3. Very enjoyable especially since they fixed a lot of stuff with 1.2. Regarding bugs... first Operation was full of it, second Operation release some month later was already much better and I didn't hear anything regarding Denova (the 3rd Operation).
4. I guess WoW's competition was on a different level than most other games but even EQ2 had a healthy competition back in the days. I feel that as the fights become harder/ more challenging we will see more competition.
5. Aside the early bugs, for someone which was never raiding, Bioware has with Eternity Vault on Story Mode a very nice entrance for any player... PvP/ "Casual", people who wouldn't raid before because the effort to get the entrance gear was already too much of an effort. You get your entrance gear in SWTOR very easy with heroic flashpoints, with this gear and with some random casuals which never entered a raid before I could see it very funny and enjoyable, probably leading some of them to try the harder stuff. With the new operation, Bioware is showing the direction towards more challenging content. Another plus for me is the small group size because everyone has to hold its own weight and can't be carried from start to finish by the rest of the group.