Your experience/opinion: Adding Bluetooth to handheld meters

[EEVblog]

Thanks for the (discouraging) input in BLE Dave, I was interested in BLE, figured it was much more interesting for the application considering the lower power consumption, a shame it's a PITA to use for RS-232...
The SPP (non-BLE) module glued-in here is used exactly as you suggest.

If you are keen to see what we had to go through to get the BLE working, the source code is on Github.
BLE simply doesn't natively support serial port mode like full Bluetooth does, so you have to kludge it into working