Fun is...subjective.
If your last car was an '87 Escort, then an RS will be a blast, comparatively.
If you drive an RS, then a WRX, the difference is night and day.
170hp vs. 245 (?) in a WRX = about 40% more HP.
No small difference, and the '09 WRX hatch is a damn fine, 2.5EJ/ almost-STi for almost 10 Gs less.