The 30D will give a lot more room to grow as a photographer than the XS/1000D.
IMHO there really hasnt been huge technology leaps since the 30D was released - additions from it to the 50D are limited to the following:
Higher pixel count - not an issue unless printing over A3
FPS - 1.5 frames per second quicker
3"LCD - 2.5 " in the 30D
ISO range - expanded from 3200 to 12800 (2 stops)
Intergrated cleaning system - vibrates the internal filter to dislodge dust.
Microadjustment for lenses.
All in all, not a huge list of improvements given the age difference! But even the 30D will be a huge advance on the XS/1000D.


