eHerms coil length for 10 gallon pot?

My eHLT kettle is almost complete. I was going to put in a custom 1/2" 45 ft coil from Stainless Brewing, but I am starting to wonder if that's overkill vs. 25 feet. I would think the wort would reach temp within 25 feet of run and it may actually be better as the wort would go through the coil more frequently instead of wasting time at temp in a longer coil.

Hoping someone smarter than me (won't take much) will chime in with explanation.

I believe mine is 25' ish (it's been in there 10 years)it's copper, it works well you can allways throtle back the pump to increase the temp ups. Nothing against stainless it's prety but Copper will give you better heat transfer and save you alot of $.

I made mine from my old IC. It's about 60' of 3/8 copper and works awesome.

Copper is approximately 20 times more thermally conductive than stainless. It seems that would make a huge difference in efficiency but there are plenty of people out there using SS for their HEX coils so I guess it works.

Mine is my old immersion chiller- and it fit in my 10 gallon HLT cooler and now I'm using it in my 15 gallon keg HLT. It works fine. It's copper, 25'.

Thanks for the input. I think I may shoot for the 25 feet.