I've got 1/2" and it's about 22'-23' with the fittings. I was worried about it being too short, but it works really well. I went ahead and put a a 5500W electric element in the HLT and I can step and heat water pretty fast.
I do 10 gallon batches and put my strike water in my MT and my Sparge water in my HLT and the turn on the HERMS and start recirculating. I can heat all the water that I need for the brew day up in about 35-40 mins (summer time).