I have a mid drive bike and an IGH is a good match with it.
You need a beefy IGH though; I cracked a couple by over torquing them. I currently run a NuVinci hub. It's a tank and has not given me any trouble (never slipped even once and I have 10k+ miles on it).
Stermey-Archer is not suitable, they can't hold up. I had issues with SRAM hubs as well. I went to a Rohloff, but moved it to my bamboo frame when I bought the NuVinci. IMO the NuVinci is the best IGH for a mid drive bike. The Rohloff held up quite well, but it is pricey.

NuVinci was designed as a transmission for electric vehicles.