Just to state, I tried Jagged Alliance Online and Back in Action both. Back in Action is horrid, they basically focused on the 3d aspect more than the game itself and tried selling it. It's worse than vanilla JA2, and I can't play Vanilla JA2 since 1.13 hit.

Jagged Alliance Online. Well, it's plagued by bugs. It uses the browser to play 3d mid-range graphics games via the Unity engine plug-in. While the actual Unity engine is great, the browser plug-in is messed up crap. I keep getting my mouse froze up, unresponsive keyboard/mouse clicks or it just plain crashes after a minute or two. Many people had trouble just loading to the login screen. The gameplay itself is summed up as Jagged Alliance Lite. It's also F2P, so expect lots of the good stuff to cost money. Like AP ammo O_0

I played Jagged Alliance 2 for only three hours. I loved it. Like, a lot. I thought it was a great example of tactical turn-based combat and I intend to play a lot more of it soon.

That being said...I have to go against the norm and say that I enjoy Back in Action just as much. Sure, it's not Jagged Alliance 2, but in this day and age are we really surprised? Do we have to go into every game remake with an insane list of expectations only to disappoint ourselves? (The exception being XCOM: Enemy Unknown. God, I hope Firaxis sticks with the basis of the game for that.)

It's like with Syndicate. The switch from tactical RTS to "tactical" FPS was a pretty damning change, but...The multiplayer of the game is pretty fun and somewhat faithful to the ideas of the original, designed with modern FPS conventions. It's not perfect, but it's an enjoyable experience.

Back in Action might not have been the Jagged Alliance 2 remake we wanted, and they may have made a lot of design choices that we didn't really agree with, but I enjoyed it. I didn't allow my experiences - however short they may have been (which I intend to remedy as soon as possible) - with Jagged Alliance 2 to cloud my perception of Back in Action. I went in the game unbiased and without expectations, and came out wholly surprised.

EDIT: GRANTED, there were a lot of things that annoyed me, like the stupidity of the enemy AI...and the AI in general.