My only opinion on it, is that I have heard from people that wobblers is common in slew lines and that would be my biggest worry. I do not have a ton of experience in the area, but I have had several breeders tell me this.
Our Stallion 'Noble Houston" is a 3rd Gen Slew (by Houston). Approved RPSI and OLD. Produces extremely nice sporthorse types. We even bred him to a 3 gen Slew mare for a 3x3 cross and the foal is outstanding. Nearly Black, 4 socks, blaze and a Gold RPSI foal. She is turning 4, was started in 2010 and is now owned by an intermediate 14 year old girl who loves her to pieces. The trainer plans to show her in the pre greens in 2011. Said its the nicest and easiest horse shes had in a long time. Jumps a 10 and moves the same!
Dont know if this helps but you can visit his site www.noblehouston.com and see the amazing ability he has to consistently produce top hunters crossed on various types of mares. One of his foals out of an Appy mare at just 4 years old is alredy a 3x WORLD Champion!!
The 3rd Gen slew mare we have (by Williamstown) was also bred to our BWP stallion Coronado WW and also produced a Gold RPSI foal. So we had good luck both ways.
Worldwide Equine www.worldwideequine.net
Coronado WW, Fal Turro WW, Noble Houston, and our newest addition the Black Grand Prix Jumper Stallion High Five !
He did have a crooked leg, not that it hindered his performance But, not something I'd want to chance with line-breeding. I never heard what it was due to, and I did hear from a reputable TB racehorse breeder that he did pass it on to a few of his get, so...