Our first boat came with a Jabsco compact electric toilet so that is what my wife became used to.  When shopping for our 36, an electric toilet was on her short list.   

I grew up with more traditional marine toilets and wasn’t all that enthused.    Our new to use Catalina 36 came with a Theoford easy fit. 

After using and maintaining both I’m pleased with how they work.    Absolutely zero problems.

I’ve used older vac flush toilets but don’t have experience to compare.

Good luck with your choice, and I hope someone can provide information on the vac toilets available.    

The attached link has some interesting information regarding electric/manual heads.  I pay close attention to Peggie Hall in regards to all things marine head.  Her book on marine heads is worth the read IMHO.

https://www.cruisersforum.com/forums/f115/manual-vs-electric-head-234571.html

Hi Ray & Laura...

What did you end up going with?

I installed an electric head in my 2002 about 10 years ago. Picked that because I couldn't figure out where to put the vacumn hardware.

We replaced our original manual head with a VacuFlush about 5 years ago and are very happy.  It uses fresh water to flush but also far less so it takes a lot longer before we need to pump out the holding tank.  I cannot tell you how much longer but think 2-3 times or so.  It is also nice to avoid the smells associated with using sea water to flush and that guests can figure out how to use it.  The vacuum pump is mounted under the V berth on the bulkhead for the forward water tank.  I admit being concerned about breakdowns so when we went to the Bahamas for the winter last year we carried things like spare joker valves, seal for the bowl and a bellows for the pump.  That said we have never had a problem with the system.
We did add an air filter to the holding tank vent since one side effect of this system is that it pushes smelly air out of the tank when it is flushed.  Filter solved that issue.

I've had several of each.  On my last boat I had Saniflo electric head installed.  More quiet than a Vacuflush.  Jabsco Quiet Flush is so loud it saves on holding tank volume as no one is willing to flush at night.

I installed a Sealand Orbit #7160 a few years ago. It works great and the sound is not bad. Unfortunately, at one point it lost its ability to prime itself. The rebuild kit solved the problem, but only for about six months. The technicians for the head have been very responsive by phone and I am impressed by the thing...just need to figure out the priming issue. 

I had my vacu flush installed 15  years ago and it is great. It uses about 1 pint of water per flush so it really extends the time between pump outs. You do need to change the duck bills every 3 or 4 years.