I don't have much experience with the supra but do with the BU. Couple of things to look at;

1. does the interior seats/colors line up.. how's the stitching? i have seen a bunch of low quality work when it comes to their seats.
2. The dash, please note that the computer screen is quite high and does block your view, especially if you are smaller or your wife/kids are driving. Its quite high up.
3. Surf gate is nice and it works. But it becomes harder to steer when its deployed compared to surf tabs
4. Dealer is more important. Both great boats, but dealer will be key. who do you trust more.