Sonic race track revisions, or just better paint jobs?

Just over a year ago I posted probably way too much text and too many photos of the 'Super Sonic Racing System' set and it's broken Sonic and tails slot cars. Well Debenhams were having a 75% off sale and still had some sets left over so I picked one up for a measly £4.50 to replace my broken set. Seems the pain jobs on the cars of this set are much better than my previous set. Either it's a luck of the draw how good the set you get is or they sacked however gave Sonic bags under his eyes and the colours all sloppy and not quite matching the artwork.

Have a look for yourself (new one on left, old on right):

There are some other subtle differences too, like the pole holding the two back wheels are longer and the characters seem to be more up right (espcially the Tails of which the old is practically facing the floor) but that's just me going into autistic levels of comparison. I haven't tried the set to see how many minutes it will actually work, but to be honest I probably won't bother. Now if the track had a loop and rings likethe original concept art that;d be a different story...