I really enjoyed PoE but some reviews state that the Tyranny ending is abrupt, inconclusive and unsatisfying. Without spoilers, how does it compare to games like:
* PoE: ending was very satisfying to me, even though you could argue that there was a major unresolved plot point about the PC.
* unmodded KOTOR 2: thoroughly enjoyed the game up until the non-existant ending. Ruined the entire experience for me. I know there is a mod for it but haven't tried it.
* ME3: I don't mind the original ending. Not brilliant but I didn't hate it either. I actually thought the amended ending ruined the pacing.
* Alpha protocol: story-wise, the ending was disappointing because you pretty much know who the bad guys are from the start. Branching wise, though, it was satisfying.

Also, I really enjoyed the combat in PoE but some reviews claim Tyranny is boring and repetitive. The only criticism I had of PoE was that it was too fast even in slow mode - I could easily lose characters before I was aware I needed to heal them, leading to a need to spam pause. But there were a lot of choices, especially in hard mode.

One last question, how does the 'level up by using' mechanism feel? The only other game I've tried that has this approach was Oblivion and I hated its levelling system because it discouraged having any non-combat major skills, since levelling these caused enemies to level too.

Thanks!

The ending of Tyranny is kind of like the ME 3 ending, insofar as it feels rushed and a bit unsatisfying since it leaves things on a cliffhanger and with a big confrontation coming up. However, it does take into account your choices in the rest of the game, it has pretty good boss fights (all of which are potentially optional depending on your actions), and well, they have to leave things open for a potential sequel I guess.
So it's really not that bad, as endings go.

The main problem of the combat in Tyranny is that there is very little enemy variation, unlike PoE, so you do the same trash fights over and over, until you get to boss fights which are pretty fun. The NPC AI is also pretty bad, so you have to micromanage them a bit too much. Otherwise, there are about as many options as in PoE, except for spellcasters, but the spell system is still pretty fun.

The 'level up by using' system actually is pretty well done. There are only 3 non-combat skills, one of which is actually the most important skill for mages since it determines the complexity of the spells they can cast. There is no real level scaling, so it doesn't affect how hard enemies are either.
Overall, it didn't feel there was much difference compared to a more traditional skill progression system.

Thanks! Very useful information. Sounds like it's not quite up to the PoE standard but still sounds like it's worth playing.