I've been pretty happy with mine so far. Only change I would make is to skin the base frame with 1/4 inch ply on both sides. Lighter and just as strong/warp free. You can still use your top of choice. The only trick is to make sure it is level and not twisted before you add the second sheet on the base frame. Any twist will be in forever after that sheet is attached. I did go a bit over board but it should be the last bench I ever need.
Build thread here;
http://www.rcuniverse.com/forum/m_10732121/tm.htm
Ken