I had a KGO in 2012. I was quite good. If you are needing back-ups/spares/extra devices, it might be OK. I suppose it depends on what you are used to.
If I was in the market for an eGo battery, I think $17 for 1,100mAh might make
sense.
With kits, sometimes they make for good value and sometimes they don't. If you would use the extras, then why not..