Its the awesome UI and the programmable driver that your buying. I ordered a storm several months ago for $50 from GG, but it was lost in the mail....
I recently bought a 120P second hand, and in the hand its a fat torch, but the electronic switching is awesome. The driver is just really well designed!. The parasitic drain is the lowest I've ever measured! 3.8uA at 3.7V. The low draws 8mA for 0.08 lumens, 11mA for 0.5 lumens. 700mA on max for 120 lumens. All at 3.9V, which is what I think I measured it at. The main feature is the proportionately reducing draw down to 1 lumen, with a small overhead noticable below this. The V10R goes lower, but it still draws 30 mA doing so.
Im currently running mine off 18650s, and with a trustyfire 2200mA, I can expect 10 days straight running on moonlight, and on a (low) maximum of 120 lumens, I can still get 3 clean hours of runtime. This is all on a old seoul emitter.
Mechanically the led sits in a large block of aluminium, which has a very large flat thermal contact area against the head of the torch. I.E. thermal pathway is very close to perfect. When I get my XM-Ls this will be modded. I would like to see how many lumens I can get, hopefully pushing the 250 lumen mark.
UI is equally awesome, 4 brightness modes each of which have shortcuts straight to them, each level programmable in brightness, and as a strobe/beacon/sos. With all the other extras in the programming menu, such as quick access strobe/beacon/sos, momentary function on the switch, battery cutoff, low level background flash locator to help find the torch at night, and maybe a couple more. Importantly the programming feels quite intuitive.
The storm can be cracked into a 120P with a 250 click sequence. There are documented cases where this has been done.
The 17670 tubes can be had for under $5 from light hound. I just machined out the inside by a mm or two and with some paper as an insulator I got my 18650s to work.
I think some members of CPF dont like the novatacs, especially the newer "consumer" run (the storm, classic, special ops, wichita), becasue they were outsourced to china for production to keep the cost down for their while the 120P, E, T, are still made in the US. The price reflects the costs of manufacturing, but the default opinion is that china must be worse....
Well if your after a torch with a very functional and well thought out UI and a very complete programming UI then you should give such a torch a go, but if all you want is just output/$$ and the normal click through UI is sufficient then this isn't the torch for you.