I have had that bouncing problem with the FW also. I put a piece of that rubbery shelf liner under it, and it acted like a shock absorber. No more bouncing, no more sliding across the sewing table.
I would be tempted to buy both, sell the FW and keep the 185. If weight is not a factor. I'm pretty sure they both have lots of accessories and parts available to buy if you want/need them later.
