Tartan 37 CB vs. Keel
Actually, the PHRF ratings are decidedly not the same. I own a T37 fixed keel (6' 7" draft) and can tell you that I must carry a lower PHRF than a CB boat.
I have sailed aboard several CB T37's and they perform well to windward with the board down. My fixed keeler will outpoint them by a few degrees and will not exhibit as much leeway while doing so - hence the lower rating.
Off the wind, things equal out. They are similar on a reach and a run, although the CB boat gives you the option of board up to reduce drag when running.
T37 #224 Higher Porpoise