I have a few questions on heat traps / heat loops.

Are they worth the cost to install?

Which is the better option, mechanical heat trap or passive loop?

I have concerns that the mechanical heat trap will restict water flow. I can not find a 1" heat trap, only 3/4 inch. Would the loop be a better choice since it can be made of 1" pipe.

If a loop is used, is it normally a circular loop of pipe or made with in a square with 90 degree elbows?