I am at level 32. I played successfully as a melee fighter/summoner combo. The hours leading up to the final battle were an absolute cakewalk considering how difficult some of the game was. Yet with so many points spent on health leech and health regen, I had gotten to the point where I was barely taking damage, and often was taking none--even in the arena fight in which you re-fight all the bosses that had come before.
I also was at level 32 or 33 at the time I go in the Hall of Echoes. I spend just 1 hour to finisch the game, but what a disappointment it was!
The final battle, then, has come as a surprise. I have at last eliminated every non-boss character in the battle, leaving only the two bosses. However, because they self-heal, it is literally impossible to complete. They regain health faster than I can damage them, so at the end of the game--in an area that I cannot leave to go and finish up the few side quests I had left--I am stuck in a stalemate.
Yeah! Linear sort end! In an area you cannot leave again! For me the most stupide thing they make in this game!! It makes no sense you cannot go back! Yesterday I write also about it on this forum:
asked myself "why Larian don't learn from earlier errors (DD and the Wazstelands you are in and can't go back!), don't listen to their fans about this and I'm afraid loose (many) fans ... so, so sadly 
So sadly because I found the game realy great and fantastic UNTIL the moment I discover I can't go back out the Hal of Echoes! Sorry I must say it here and now... it makes me cry... so a fantastic game and than ... crack ... the game goes to pieces at the end, after playing many hours! 
I can forgive bugs, in the sense that they are accidents. They are not purposeful design failures, but flaws that appear in many a game, particularly ambitious ones like RPGs. But I can't forgive purposeful design decisions that force the player to revert to an old save game and lose hours of progress due to conscious design decisions. Divinity 2 has some excellent qualities, and it's easy to like in spite of its many, many flaws. But the last several hours of the game are a failure of game design....
I totally agree with ursoward : ... "design decisions that force the player to revert to an old save game" ... if I wish to finish more side quests ... because WHO would expect that you can not return????
