Smoke: I agree with most of that, i have only gotten about 25% through SiN 1 (i'm very glad it came with Emergence) but i do miss Blade's talking.
For me though, the lack of story really didn't bug me at all. The outright stealing from F.E.A.R and HL:2 bugged me the most, but i think the game made up for it in it's own way.
1. It cost me $18, compared to F.E.A.R, this game was very worth the money.
2. I'm a massive stat-whore, and SiN definately had the stat-tracking.
http://img.photobucket.com/albums/v404/Sylaran/Game%20Screens/Sin10.jpg <- my last run through of SiN stats.
3. Because of hte length, the game is very replayable. I've already beat it twice, the auto-adjusting difficulty makes a ton of difference. My first time through the game, for instance, i only killed 44 chaingunners, my second time through the game I fought nearly 100. (There was barely a single "grunt" after the first major ugly ass boss) The game is also overloaded with "YOU FOUND A SECRET!" and it lets you know about them. Some of these secrets are just hilarious:
http://img.photobucket.com/albums/v404/Sylaran/Game%20Screens/Sin05.jpghttp://img.photobucket.com/albums/v404/Sylaran/Game%20Screens/Sin06.jpgSo are a lot of the "phone calls" (Take one of the 4 digit numbers you see on posters and enter them into one of the terminals, hilarity)
For Me, SiN Emergence was all about the small moments and the way the guns just felt incredibly right. Overall the game was far from being something "amazing", but i felt like it wasn't trying. It was an absolutely awesome, short diversion of an FPS, which is why i bought it.
Artimus: HL2 is down to $30 now, i'm sure you can actually get it + extra's for cheaper right now. I highly reccomend it, the Source engine is also remarkable in that it scales, very, very well to slower systems.