I would probably wait at this point to see what Bitmain and Sfards releases in the next couple of months.
Yeah, the S5 is getting old, i'm waiting for the new hardware too.
I see some guys create a chip who can do bitcoin and litecoin mining at the same time. I think that is the future. Is better wait a lil bit and buy when the new hardware came to the market.
It's not really a new idea... in fact SFARDS, the company that is making the BTC/LTC combo is composed at least in part by gridseed as far as I know. Gridseed, if you recall, made those dual chip orbs last year.
As far as it being the future, I'm not entirely sure about that, but it is definitely a pretty interesting project.