Great start Adam. This type of investment in technology infrastructure is brilliant in my opinion.
In general I think it's well designed, easy to navigate and as the content builds will quickly become a 1 stop shop for all.
My constructive criticism on the race previews is the design piece needs to be improved with the speed maps. Putting up a screen shot of the iform speed map, is to put it bluntly, cheap & tacky plus the horses names aren't even below the horse. This needs to be better designed and the horse names included.
When viewing on an iPad the main menu bar at the top of the page doesn't resize correctly and puts the menu over 2 rows, you may want to let your designer know this as I would expect many will access this from a mobile device and having consistent formatting regardless of device is really important.
Greg is obviously an experienced broadcaster so having him deliver the previews is great. Hopefully that will extend to all interviews, as without being disrespectful to those previous but the interviewers on trots TV prior weren't experienced and the quality of the interviews was poor in my opinion.
All in all a terrific start and I look forward to watching it evolve. Well done to all involved.