Same damping system ( Tora 318's ) as the Rev's, which is the important part.
Rev's are built to keep the weight down, so light weight magnesium lowers, Alu Stanchions, compared to likely steel lowers and steel stanchions. Rev's have a fancy low stick coating to to reduce stiction / look nice.
The Tora's are likely stronger than Rev's, but also ofcourse heavier.
They won't have steel lowers - these days even the cheapest forks have cast magnesium lowers as its very simple way to make them.
Edit - actually it appears Dart's have cast aluminium lowers - either way lowers are cast.
However they do have steel steerer tubes and stanchions. Crowns are all aluminium even on Darts.
One thing to note though - RS list the Tora as an XC fork, whilst Revs are All-Mountain. This might mean they aren't keen on warranty repairs for bust Tora's caused doing extreme stuff.
I've not used the Tora, but I have used both Recons and Revelations and if you can run to a little more, the Recons are fantastic at the price. A bit heavier than the Revs, but work pretty much as well.
The tora's are basically an all mountain fork, they're listed as XC 'cos (as I take it) this covers the greatest amount of riding types/styles and they go down to 85mm which the rev's don't. If you look carefully at a tora or recon, they're really sturdily built with tough lowers/steerer and the crown is reminiscent of the marzocchi allmountain (and above) forks being very deep, also they have a big section holding the stancions which is a key element to strength and flex resistance. They're designed to take some abuse either on the maintenance or riding front.
Motion control is excellent btw, very well controlled and bob resistant, though the standard damping gets good reviews both in the press and from users.