Info on Custom Muzzleloader

I’m hoping that somebody has some information on October Country Muzzleloading. I stumbled across their web site and noticed they build custom .69 caliber English Sporting Rifle muzzleloader. I really like the idea of throwing a huge chunk of lead down range out of a muzzleloader. I called and spoke to the rifle builder and he seemed on the up and up. I was just hoping that somebody has one or has shot one and could tell me their thoughts, before I put my money down. Thanks for the help.