I think I will start with the larger heavier versions since modeling them one way or the other is really no different (invested time). If we find that the model is getting too heavy then I will go back in and create the low poly versions and then offer the user the ability to switch between modes, this will give the most flexibility.
Some people won’t care about the blocky look of the low poly fittings while others will. After developing these extensions now for ten years I have a pretty good feel for how the power users will respond and the opinions will be split and some will demand one or the other.
I do my best to make everyone happy, and that usually means more work for myself. A happy customer brings a certain satisfaction that is hard to explain so that is where I am at.
One thought on plumbing. Its been noted in other posts as well, usually pipes arent drawn. There is a thread about the VBO plug in with some wonderful renders. With regard to single family homes that are probably the bulk of Medeek users. I would say the ability to do a Hydronic layout of the pumps and manifolds might get some use. Ive done a few in custom homes I built where we did the system from scratch. There are manifolds now days that simplify the assembly. I always did the whole thing in copper but I would consider Pex on the next one. Space seems always limited to arrange the pumps and manifolds. A layout before ordering components would be useful. I have no suppliers to recommend. its been a couple of years since the last one and its an area that is changing constantly.
I seldom model pipes or duct work. Three mechanical contractors will do it three different ways. But in tight installations they might need some accurate details. Commercial is a different story.