A few questions
Are the reviews true?
Is there an online ranking system?
Is the online play fun?
Are the teams balanced?

Answers:

Make up your own mind
No ranks, only leaderboard
From what i hear Yes
The delays were for balance so id say yes..

Reviews.. not true in any stretch of the imagination, but that's my opinion, of course... and I never played timesplitters and had no prior love affair with the devs.

Online ranking system... the deepest I'VE EVER SEEN! This baby tracks everything right down to the distance that you've walked in meters...phenomenal stats tracking and awards.
You are only "ranked by map and game type individually.. not overall rankings although each stat (and there are tons!) has it's own leaderboard.
Online play is super fun and different depending on which side you choose.. you really do have to play differently.
So far, and it is early.. the teams are very well balanced, although right now, people seem to join the mantel team first, I think that is because nectar is cool and the mechanics of being a mantel tropper is what people are used to because of the demo. But in all the games I've played it's been a 50/50 split between the mantel winning the match and the rebels winning the match... so with only a day to judge by... yes the balance is very good...

Worth it.... People that suck at shooting games might not like it. They get shot in the back OD, controls will go all overdose funky, they'll die like that a few times in a row cuz they suck at shotting games, and then they won't have fun and probably call it a bad game...
If you know how to play a FPS, you will most likely adore this baby!

If IGN gave GTA IV a 1.5/10 would you agree with them and not buy the game? If yes, you need something called a personal opinion IMO.

it's hard to believe this many people based their opinions on a game from a review.