I've got the same issue.

Currently have a K800i which I've been using since it first came out and absolutly love it! It served me very well however its getting a bit old now and I'm thinking about getting the new K850 though bit concerned on its reliability.

I've been hearing a lot of horror stories where the phone has huge issues soon as its taken out of the box. Ie, turning off for no reason, dust under lens cover, bad quality photos, dark photos etc.

I've tryed it out at a phone shop the other day and it feels great to use, very friendly and simple just like the K800 though I also took a photo and was not overly impressed, also was testing out nokia n95 8gig and that took much better photos at that time, note I didn't play with any camera setting on neither phones.

Is it worth upgrading to K850? And has anyone had any issues with it?

Cheers.