Ended up going down the TDI route with a good instructor. Most of my diving's solo, even though it's with a bunch of people on various boat who also generally dive on their own (probably as much to do with local conditions as attitude).Same story here. Thought I was good until I did Fundies. Have passed tech rating after three tries. Wanted to go for Tech 1, so I needed the cert. Otherwise, I would not have cared about the cert. Stil practicing skills every dive to get better.
Funny thing is, I don't want to dive GUE CCR so I have no use for the Fundies cert anymore. I did however prepare me for the next step that is JJ-CCR. Without it I would not have been ready to take that step.
Have dived with GUE divers which is kind of fun, but you're very much beholden to the whole synchronised team diving thing. If you're the type of person who's interested in looking at a blenny/whatever for 10 minutes, there's a team pressure to move on.
Their rebreather... odd. Rest of the world dives with "normal" rebreathers with a couple of 3 litre cylinders and a side-mounted bailout. GUE like to be different, maybe it's the equivalent of bikers who like agricultural Hardly Davidson crap; demonstrate your commitment to the club. Inverted stages make shutdown drills a bit easier; donation of gas is just hauling out your bailout regulator, yet all of this has to be like open circuit...
Choosing a rebreather is part of the fun. No rebreather is perfect as each have their benefits and drawbacks -- quick Revo plug here! Doing your MOD1 training is fun too. Then practising with other people or just diving solo off a boat.
And what's wrong with sidemount? It's a very good tool for a lot of jobs, even general purpose boat diving. It's particularly good for mounting bailout cylinders on a rebreather so they're out of the way and streamlined. Don't want them snagging inside a wreck.