2.4 GHz types tend to be more reliable & have better range.
They differ in whether or not they handle groups – only relevant when you acquire more than one off-cam unit.
The next variable is latency of the signal within the link. It’s worth searching for a really low latency unit to preserve your max sync speed. See & scroll down:
Another good summary site:
If I was looking now, I’d consider the Comlite / Ojecoco 430 units or the new Phottix Ares triggers.
For slightly more, offering genuine TTL pass-through on the Tx – Phottix Strato II.
c4 yrs ago, I went with Yn RF-602s and was extremely pleased - though now v slightly slow. Later I moved over to Phottix Odins which are simply sublime. Good luck