Not that anyone asked my opinion (and when has that ever stopped me?), but I tend to lump a stainless steel air filter in with those stainless steel oil filters that also claim power increases. Yup, unless you're ham fisted enough to poke a hole in one, they'll probably last forever. Of course, the same goes for a properly maintained K&N. BUT, unless there is some magic superconducting electromagnetic force field that they neglected to mention in the sales pitch, the higher (claimed) flow comes at the expense of effective filtration, just like that metal mesh oil filter. If the aim is to just maximize flow without regard for other factors, then I submit I can save the $90 plus $130 for the back plate, and the $200-$300 for the oil filter, and just not run filters. Definitely won't have any filter induced power losses that way. BTW, how about one of those velocity stacks that were all the rage on the carb bikes many years back? No restriction, and you could get a nice metal screen for those to keep the boulders out that wouldn't affect flow much. Looked fine on those show bikes, sucked (pun intended) big time on a real street bike.
I'll repeat my earlier suggestion; stick with the Ventilator for the best compromise between effective filtration, flow, and ergonomics if you plan to actually ride the bike on a regular basis. If you want to spend your money on something, buy a K&N element for it, $59.95 MSRP at your friendly Harley store.
Jerry