I think you'd be hard pressed to outdo a keelboat for ultimate upwind angle. Once moving big heavy keelboat can keep can chugging upwind in apparently no wind at all.
Dinghies like the laser also point very high.
Their overall vmg is also very good, especially in gusty light wind and constricted waters.
I race against a 3 man racing keelboat every summer and it's always a duel of opposites: I get passed on the upwind he gets passed on the downwind.
Catamarans point about the same as sailboards but have amazing all-points-of-sail vmg and aren't really affected by lulls.
With my current mediocre raceboard setup with a 7.5 I don't have a chance against most boats unless it's at least 10 knots.
The greatest advantage I see versus a similar sail sized dinghy (laser) is ergonomics and ease of use in 12 - 20knots and over when boat handling becomes tougher for an amatuer sailor. You lock into a raceboard and it gets more stable as it goes faster, a laser sailor is always working.
In the right conditions, kiteboard course race boards and formula boards are hard for anything to match.