Yes, I think they're worth the extra money. Mk5 Gti's are getting quite cheap now (in fact I'd quite like one to alternate with the ED30...) - ED30's are slowly being dragged down, but still command a premium. Remember, the engine is practically a detuned S3 engine.
The one you've posted looks a decent price. There's no options on that car by the looks of it, so you could easily add an armrest, cruise control, RNS, even highline computer (if you want to later on...). The wheels look good - no signs of kerbing (maybe been recently refurbished), centre caps look new (no corrosion), but the only negative (other than the dangling air-freshner) is the flaky rear caliper on the drivers side.