So this monday i will finally be able to walk again after a month of having to stay off of my right foot due to a sliced middle toe tendon kitesurfing at the beach.(sea shell) I just got my mbs core 95 and am going to be landboarding all next week.
I just have a couple of questions. Im going to be flying my 12 meter LF Havoc which is a SLE, and winds next week are going to be most likley the usual 15-25mph.

1. What kind of speeds can i expect to hit

2.is it possible to stay up wind going back and forth on a landboard, or do you eventually start sneeking down wind.
Im going to be riding on about 1 1/2 acre of grass he shape of a rectangle. Im just concerned about how much room i have to ride.

Your landboard is just like your kite board except you don't need quite as much power to ride (your already standing up and don't need the extra power to keep you afloat).

Riding upwind is just like on the water .... but may be easier to do because you have much more grip on land than in the water.

General rule of thumb for speed is that if your kite and vehicle are max efficiency, you can get up to 3 times the wind speed. Rider skills, terrain, weight, size of kite, and more all play into the final speed so take the 3 times number with skepticism. Usually you can hit 2 times the wind speed pretty easily which is plenty fast for a land board but just cruising with a buggy.

Just a general number for you to start with, actual experience will most likely be different.