I bought my first pump simply to eliminate an elevated HLT. It was a good upgrade and made my setup easier to use and safer to be around. I'd like to think that every thing I upgraded or changed led to an improved process or product, but there are a lot of things that are just nice to have.
One of my pumps is a March with a Chugger stainless head added. The stainless is sure nicer, but there is no benefit to the process itself as the poly heads work the same. If it weren't for a generous friend giving me the stainless head, I'd still have the poly and be working just fine.