Whilst these threads can lead to interesting debates, I think it would perhaps be better not to include the same rides again versus other combinations. Otherwise we've got most of the first page clogged up with a vs b and b vs c all at once, all started within days of each other. Just a thought?
Original Test Track was better than current Test Track (neither version are even close to World of Motion), but they're both better than Slinky Dog just by virtue of being less generic.
Slinky Dog is more or less a standard exposed track family coaster with little theme beyond the unique ride vehicle. You can get a similar experience at any number of amusement parks around the country.