I've talked to more than a couple of gun shop guys who say that the Echelon is not exactly flying off the shelf. Springfield probably should have released a compact G19 sized model along with the full size. But I'm not so sure that space is as popular as it once was, given the new crop of slim compact/upsized micro pistols like X-Macro, Shield Plus and Springfield's own Hellcat Pro.Springfield introduced the Echelon recently. Hopefully aftermarket and additional OEM grip modules will be coming soon.
I actually won an Echelon in a contest when they first came out. Put 50 rounds through it and didn't really care for it. I traded it off a couple of days after I won it. I don't think it's a bad pistol, it just didn't do anything that my M&Ps, P320s or Hellcat Pros don't already do well.