I use optimium nutrition whey, have done for past 18 months .
Yes its not the cheapest , but mixes very well, taste's good and i've seen good results over that period.
Could i have seen better results using a different brand ? who know's
The other 3 in my opinion , waste off money and havent used any pre workout for prob getting on for 2 years,have a redbull or nodoze, there cheaper, i wouldnt reccomend it but if you need a pick up go for it.
If i carb up few hours before i workout , or do high rep i tend to get a bigger pump, but that is all it is a pump.
As soon as people "wise up" and stop buying this crap, maybe then there come up with something that actually helps us, and is good for us.
Untill then if you need superhydroxyjack3dmusclemajic to get under the bar, they've got there place, BUT YOUR NOT EATING PROPERLY