Well, if all your looking for is a narrow EGO style battery, I would say that the Innokin VV4 works better than any other choice out there.
I used the word 'Great' as it would only pertain to an EGO style stick battery.
An iTaste VV4 and a matching diameter Kanger Aerotank Mini is certainly not my all day long vape, but fits the bill when you want something narrow and light weight when you go out of the house for a short stay somewhere ... nice front pocket setup for the 'short term'.
Just my opinion ... and all the OP was asking is what is the amp limit on these small EGO style batteries ... Again, 4.0 amps on the Innokin iTaste VV4.