Channel Switching Relays Slow; What Do You Use?

[tictac]

Im presently using 2 Weber Relay boards in My Dumble clone. They seem to work OK but they seem a bit slow, the switching is not instantanious. I've got 7 volts DC for the switching supply and it drops to around 6.5v after the relay is engaged. (6v relay)

So I don't think it's a power supply issue. What are the best type of relays currently being produced? Are there are S/S relay modules or other new technology out there that would give better preformance than what Im currently experiencing?

thanks