I must say that all the shocks on the market are good just depends on what you are looking for.
xray easy to adjust
trf shocks super smooth and farly easy to build
losi type r shocks easy to build and smooth
serpent easyest to build the same
hpi shocks on worlds cyclone about the same as trf
my vote is serpent shocks because its most important that all shocks are the same and they look like the easyest to build that way. not sure how good they are as I'm waiting on the electric car
thats how I see it