Superlyte27, let’s look at your profile shall we, a technical diving instructor and salesperson based in Florida who sells the Optima (by the way the web link to underwateradventures does not work), where in that market the rEvo is a pretty major player and competitor, so we should first acknowledge this is the position you come from, you probably think it is in your interest to deride the rEvo, though it is rather unbecoming of you. I think that generally puts your comments into perspective, ie a bitter and twisted instructor and dive gear retailer.
As for your claims regarding build quality, just how do you suggest the case containing the lungs be constructed, CNC machined out of block titanium, stainless, or maybe aluminium, no that would be just ridiculous and most inefficient. Just because something is CNC machined does not make it superior. Just a note the manufacturer behind the rEvo in Belgium are specialists in precision machining and manufacturing, I think they would know their **** when it comes to the best way to manufacture the rEvo.
Your comment about WOB is just the typical unfounded BS that someone with a vested interest in diminishing the rEvo performance would come up with and is just crap, and you would realise it if you were completely honest with yourself.
Me, yes the rEvo is the only rebreather I have owned and trained on, and the only rebreather I intend to own, I can't afford to be upgrading to the latest and greatest every few years after all diving is just a recreational pursuit for me, one which I very much enjoy and have no intentions of ever becoming an instructor. I have had my rEvo 5 years and approaching 400hrs on the unit, mostly diving and exploring deep reef and wrecks. In that time I have not missed a dive because of the unit or hand any major incident involving the rEvo. I have now had the opportunity to try a number of other rebreathers, dived with other rebreather divers diving other units and pretty much had a close look at most of the units produced by the major players, based on this I am very happy that I went with the rEvo 5 years on, and if I was making the decision today I would still get the rEvo. So I am pretty happy with my choice, it’s not perfect there are a few little things here and there I would like changed but they are not biggies.