I recently got my NEC 2500a,
It's brilliant, burnt around 15 DVDs so far, no coasters and brilliant quality.
Its a bit dodgy for playing DVD's but that doesn't matter cos i have a seperate DVD drive. Burns CD's ok. I'm using datasafe ritek (G04), works fine for me despite the majority of people saying they don't work well with the NEC, although they are a bit pricey.
Hope the choice you make, is the right one......
(I got my NEC from http://www.blankdiscshop.co.uk and my media from there, it is an excellent shop.....)