My daughter and I have been using Evods for a couple of years now, and really enjoyed them. We have had minimal problems with either the tanks or the batteries. I try to order from vendors that stock genuine Kanger parts, especially coils. For us, it is worth it to get genuine replacements.
We prefer the Evod Glass over the Protank 2 Minis, which I had originally gotten along with our first Evod starter kits. You will probably want to get a glass tank eventually. The original Evod tanks, as well as the Evod 2 tanks that come with the Evod 2 starter kits, are plastic, and can be damaged and/or destroyed by certain eliquids such as cinnamon and citrus. The Evod Glass comes with Kanger dual coils, but they do work with Kanger single coils. I prefer the Kanger single coils, whereas my daughter likes the dual coils.
We have successfully been using the Evod tanks on Evod 650 mah batteries with eliquids at 50/50 pg/vg and 30 pg/70 vg with no problems whatsoever. Some eliquids, such as darker, sweeter flavors, will gunk up a coil sooner than lighter, less sweet flavors. The Kanger single coils can be cleaned/re-wicked/re-coiled, depending on your preference. I have had some success in getting an extra 2-3 uses out of a coil before I pitch it, just by cleaning. Not so much for the dual coils - so far, just using a fresh coil has been working better for us than cleaning.
Have fun with your Evod. Play with different pg/vg and nicotine ratios until you find what works best for you. Get familiar with your equipment. This will stand you in good stead if and when you decide to upgrade.