Good question ... I bought one for myself. I set it up - and go. But over time (a short time it turns out) I put too much pressure on my shoulders by elevating the table to the machine deck. I needed to sit alittle higher than a normal chair when using one. A TV show I saw had recommended a table sitting practically on your knees for ergonomic benefits. I thought the program was crazy - until my shoulders had issues. Not so crazy.
I use an old cabinet table - cut down to 28" tall - my chair is pumped high and my shoulders are better. Not perfect. If I had only listened to the expert I might be perfect - right now I am just better.
Listen to the ergonomic experts .... save your hands, shoulders etc. Best of luck in your decision!