i do not own one, but im interested in what others have to say. CDNN has these rifles (the ICON), and theyre $399. it tempts me. i think its an efficient cartridge, but after looking at the hornady manual, id say that the only way the 30TC has an "advantage" over the 308 is by using superformance powder, or something similar. i do think the factory ammo is loaded pretty hot. so if youre shooting factory loads it will perhaps give better performance than a typical factory 308 load.
recoil ... im skeptical that it kicks appreciably less than the 308. its just a function of physics. perhaps if it burns a little less of a higher-energy powder. although ... those ICONS are heavy! thatll cut down on recoil to some extent.
future component availability .... i dunno. theres a reason you can get em so cheap right now. i seem to love obscure calibers, though, so i still might end up with one.