No need to inject... the BEST vape possible depends on: the right amount of juice, in the right place, and having the right atty resistance to power setting... not in that order.
1. atty resistance to Power:
You have an eGo, which is around 3.1 to 3.4 true voltage. So your atomizer has to be within the range of resistance for that minimal power. An LR atty (1.5 to 2.0 Ohms) will give you a hotter vape and more vapor... some love that, and for some it's too hot. The 2.0 Ohm LR will give a little less heat, and I recommend that.
I also prefer an atty in the 2.2 to 2.4 Ohm range, often called a "regular" 510 atty.
(btw, you can get a 901 adapter (510 to 901) and try 901 attys in similar Ohm resistance ranges as above.)
But anytime you get resistance above 2.5 Ohm, you are wasting your time, as the Power is not sufficient.
2. the right Place in the atty for the juice... it will vape just about anywhere, but i recommend right on the bridge... "top feeding".
3. How much juice: this is very important because too much will cause flooding... (you can just blow the juice out of the atty with your mouth to remedy this.... take it off the eGo and blow on either top or bottom, with a napkin to catch the juice.
I recommend 2 to 4 drops...
Too much = flooding = gurgling = less vapor
Too little = burning = harsh taste
If you are using a normal juice bottle, the drops are pretty similar... more PG in the juice makes it more watery and VG more dense. You just need to get a feel for the right amount.
IMO, the best vape may take more refilling, but the vape is worth it. Find what that is; to me it's clouds of vapor and optimal taste.