I have baught a sony hdr xr 550e. The main things are:

1- Optical stabilizer (some have only numeric ones)
2- Size of CMOS (the bigger the better, helps you to capture good movies with low light)
3- Optical zoom (gives you 10x optical zoom with wide angle).

The only mistake that made NTSC you have to go to model 550V or you have to try to sell it like me!

The professional ones support both Pal and NTSC. The price of this one is 4800 in DOHA. I'm tring to sell it for 4400.

Yours,
Soroush