Honestly, I have been using the eleaf 30 for all my subtank needs with no problems at all! .5 ohms handles like a dream and usually lasts me two working days before a recharge which is a huge plus for me.
I liked the eleaf so much that Ive bought another one for my wife, as well as upgraded mine to the 50w! Decided to be good to myself for 3 months smoke free haha.
I havnt tried the Aspire subohm battery but I would assume that it would work just as well, aside from not having the customization that the eleaf or another VV/VW device would have but for the price you really cant go wrong.
What it would come down to basically is what do you like more? something that feels cigar-ish in your hand, or something that feels like a battery pack(Or one of those huge new car FOBs that every manufacturer seems to use now-a-days lol)
Or, the 3rd option, which to quote the famous taco girl from that one commercial... "Why not both?" *Crowd cheers!*