bbmac,
Sorry, with being a new member I can send private mesages,yet.
So,
I use FX iCube as an IB to LMAX. I got the same platform same execution costs, but with a much smaller minimum ammount. No problems untill now, everything looks good.
It's a very good service provided by lmax in terms of spreads, costs and liquidity. The only problem is that they have a 10k minimum on each account. But I opened an account with them through an IB, that has no minimum and same costs.