Welcome and glad you joined.
is an
istick 50w an upgrade from an Evod vv 1600?
Yes.
You should be able to increase your vapor production with the Evod in a number of ways. Use a liquid with more VG present is probably the easiest.
When you produce more vapor one tends to change/sacrifice other parameters such as taste, amount of e liquid used and wear/tear of the battery, heat production may increase etc... Vaping is a balancing act that you have to decide what your looking for.
Suggest you visit another vape shop and ask if someone can show you how to increase vapor production with the equipment you now own.