There are also a more recent variant that are called Torx Plus that are slightly different and are supposed to be more durable and aren't supposed to cam out, or twist up and out of the head, as easily as the original Torx. From what I have read, they will fit many Torx head fasteners but not all of them and they usually provide a more snug fit. I eventually want to get a set to try because even with the high quality bits like Wiha that seem to fit better, you still encounter the occasional bit where there is just a little bit more play, or slop, in the interface than what is probably ideal.
I've had many different types and brands of Torx from multi bit sets to individual wrenches for each size. I've had sets from Home Depot, Lowes, Ace Hardware, Sears, and others and the individual wrenches usually seem to be a bit higher quality. The small micro-driver sets usually seem to be a bit more hit and miss. I did recently come across a brand called Picquic that is made in Canada. It is a screwdriver handle that has holes around the circumference that the bits slide and store in. The bits seem to be pretty high quality from what I've seen so far and they were available in my local Sears store. There is a small version that has T5, T6, and T8 along with philips and flat bits. There is a bigger one named a Multique that has T6 and T8 bits that are longer. These aren't perfect since they are likely missing some sizes but they do seem quality made and it's my experience that the small bits are the most important for being well made since the screws are more delicate. The bigger T10 and larger bits usually have stronger screws and don't seem to have problems as often from what I've experienced. Just thought I would throw it out in case someone needs something local or happens to see them in a Sears or elsewhere and wondering about them.
