I use the
Losmandy V SBS plate and have had no problems with it. It's for a Vixen type dovetail. It's a lot lighter than adding an extra 20Kgs of counter weights and it's a lot closer to center as well. I believe I have some intermittant flexture problems but it's more likely to be crappy plastic screws on the guide rings rather than the SBS bar arrangement. I can also fit a load of stuff between the scopes like, camera control boxes, dew heater control boxes, USB hubs etc etc.