Pretty common. I haven't used the program myself, but I have worked with editors who have.
As Michael has said, you can send a wireless feed to the camera as a scratch track. I'm assuming the camera in question is a DSLR since you mentioned that it may be cumbersome. If it is a regular ENG/EFP camera then the everyone involved would be used to the sound recordist/mixer connecting a cable to the camera. Just remember to check on the wireless send every now and then to make sure that sound is going into the camera. A safe option would be to use the wireless send as a director's feed as well. Meaning that the director is listening in on the same feed you are sending to the camera. That would ensure someone is at least monitoring the feed. Then you just need to worry about the wireless batteries dying.
For PluralEyes to work, there must be audio recorded on camera. And it is best if it is the same as what the sound recorder is recording. I'm told that it is a 50% success rate and that is actually pretty good in terms of saving time for syncing.
Don't forget to slate and if possible link TC between the camera and recorder. Every little thing you do helps post. That being said though, its imperative to have a post-production meeting before you start production and let post dictate the workflow. There are various ways to sync up dual/split system recordings these days and the workflows are quite unique. For example if you were to use the Field Recorder function in ProTools to sync audio, then data wrangling and editorial must be very careful in preserving metadata.
