Funny enough, I've been researching this light today.
1. Don't run at 100%, unattended
2. Some complain that the switch requires a good deal of pressure
3. No memory
4. The replacement (with R2) Jet-I Pro is already out
4a. If you want one, don't delay too long.
I don't think the Jet I Pro is supposed to be a replacement for the Jet I MK. The larger head of the Pro puts it in a larger class of light.
As for memory, that's not a big deal with this light because you can program the A-B-C settings anyway you want, so it becomes a light that's individually taylored to turn on at whatever setting you choose.
Since the turn on setting (A) can be set to anything you like, it's really no different than a memory light.
And finally, I'm sure someone else figured this out as well, but I played around a little tonight with the switch and found that what makes the switch feel a lot better is to cut a piece from an expired credit card into a round chip that will just fit into the inside of the rubber button. Sitting between the rubber and the switch itself, it adds just enough thickness (about 1/32") to make the switch work more like I thought it should.