Sailingfool, I think that you have run into a poorly sailed Tartan 34. The 34''s are not very good in light air but come into their own in a moderate breeze. In a moderate breeze the 34''s are quite fast upwind for their rating and can sail dead downwind quite well with their boards raised. In a moderate or above breeze, a well sailed Tartan 34 can be very competitive under PHRF if properly prepared and properly sailed.
The same can''t be said for Pearson 33 or 35 or Cal 33 or 34. I would say that the Tartan 34 is better constructed than either the Pearson 35 or Cal 34 and on a par with the other two boats you mention.