tough question and you will get a million opinions, its not a black and white answer i can give you.. i'm very curious to hear others opinions on this cause i'm sure we will get some diverse answers.
if you ask most guys they would say switching things up keeps the body guessing and things clicking differently.
there are so many different AAS out there i think guys should try different compounds, brands, etc... i think running the same thing over and over again you would get a point of diminishing returns quicker.
they all worked but in different ways for me, they all have pro's and con's. so IMO you should def experiment with different compounds and not run the same thing over and over again. you might find that you like something else even better.. you can't know unless you try
the thing that impressed me with var is the strength gains i got on it. you hear a lot of stories how its weak but boy was my strength through the roof on it. so had i not tried it i would of never known