Installation of Race Technology's DASH2 is now complete, and all appears to be working well. I ended up keeping the standard MX5 sensors, which means that the calibration is a little crude; but hopefully sufficient for my needs.
The reason for getting the DASH2 was to provide instant sector/lap timing information from Race Technology's DL1 data logger. If anyone is looking to do the same, Race Technology are just about to release two versions of a new DASH3 product specifically targeted at showing the data that's being logged by the DL1.
Entry forms have now been sent for the MaX5 race at Snetteron on the 25/26th May. Going to be interesting to see how the tyres hold up to a 30 minute race.