I don't have much experience with racks.
Only with cheap Alesis racks for e-drums, and those were worthless.
This however, is a whole different ballgame.
I only use 2 shortest size curved pipes with connector and clamps to connect some stands together for stability, and mount things on it. Works good.
I could use 1 single longer pipe, but that would be problematic for transportation.
2 x 60cm pipes are much more flexible in usage.
The clamps are expensive. There are cheaper alternatives out there, but I'm not going to experiment just for a few bucks difference while knowing this is the best option.
But take note: the beautiful chrome finish will be chipped off rubbing against other metal very quickly if you put these in a hardware bag without any protection.
Immediately after the first time you transport these,
The rack pipes are better resistant to that but not these clamps.
I recommend a mic. stand bag with seperate compartments because some of them they got room for rack pipe transport with the clamps still on it, or seperate each one of them in a normal hardware bag with a blanket.