I just got my unlocked C905 this morning and I have to say It's Awesome!
I even found a great free GPS program that works offline!

My qualitative review based on 4 hours

Observations:

• I see why some people complain about the battery cover. It is made out of a fairly soft nylon plastic, however, it is quite secure. I actually have a fairly difficult time removing it.
  
• What people are referring to when they say that the slider part jiggles is actually barring wobble. Basically, there is a small(very small; less than .02mm. Yes, I measured it) amount of play between the steel tracks and the roller barrings for the slide --Not a concern. On a side note, it has much less wobble than the LG Scoop.
  The main reason why people note the wobble is because of the rigid metal-on-metal feel to it. Many other slider phones have a metal-on-plastic wobble which is much softer (and potentially less durable).
  
• The number pad does worry me. The type of plastic used isn't very durable. (prone to tears/wear-through) That said, since it's protected by the screen portion of the phone, that shouldn't be a problem.
  
• I'm skeptical about the camera shutter. I wish they were more modest with the design. It's somewhat complicated and made out of extremely thin sheet metal. I can't exactly explain why I'm concerned about it but something tells me that this will be the first thing to break on my phone. It's construction is too complicated.
  
• I'm too lazy to do a software/functionality review.

Edit:
lol, While I was writing this review my phone decided to auto update from the network. I don't have a data plan so it just locked up... I solved the problem by re-flashing the phone but I hope this doesn't happen often..
The whole black screen/failure to boot thing scared me.