I've got a basic unisync to balance my twin SU's.

I had an Innovate LC-1 and have now upgraded to a MTX-L. Both worked well, were easy to use, and can be used to help select a needle and dashpot oil that is correct for your setup.
For datalogging I used my phone to video the display mounted on the dash.
This came in handy when my exhaust clamp unscrewed itself whilst driving at 80kph. The exhaust clamp fell off and I was able to track where it fell off by looking at the video. Then it only took about half an hour to find it on the side of the road.

I have a LM2 and use it regularly for tuning bith my own and customers cars.
I find it really good and very reliable.
I bought the kit with the hard case and extras including the suction mount and tend to use most of them.
Probably have had it 4 years now. Had to replace the sensor once but that was my fault, it didn't like getting very very wet with cold water when it was hot....

There is an inductive clamp that came with mine that clips onto a plug lead, much the same as a timing light. This plugs into the unit and you can then log rpm and fuel mixture.
On mine the info is stored on an sd card which you then plug into the laptop.
Most of the time I just use it with the o2 sensor only and take it for a drive, figure out what's going on and change needle, spring and oil to get it spot on.