The new one(627x) has a much better battery life than the original one. For me 4 hours is enough, it just enough for one coffee session.
Truth be toldI do not consider anything of the size of portable amp as it is not something anyone is going to comfortably put in their bag and listen to music, there is just too much hassle to change track. What amps like portaphile are designed for is to give you desktop performance with the option of not been tied down to your table.
At the end what it comes down to is sound which I am sure it will do just fine.
Whilst the original 627 is undoubtedly a superb sounding headphone amplifier, how many users can honestly tolerate 4/5 hours run-time before the battery needs recharging?!? I thought I could. So whilst being utterly beguiled by the 627's sonic ability, I became very frustrated having to recharge it so darned often. Now the revised 627X offers a more satisfactory 10 hours run-time but for a $100 premium. In my opinion the Pico Power sounds virtually as good as the 627, is slightly cheaper, has better build quality and form factor, and will run for 40 hours on a pair of 9 volt batteries.
I still really enjoy using my 627 at home, plugged into the mains as a bedside amp, but for portable use the Pico Power is unbeatable.