[Alan57]

Matt
Yes, as I recall and I haven't dived a Dolphin for 5 years, so they may well have redesigned it, the cleaning of the 'lungs' was fiddly and required stripping down the set completely. The correct jet had to be chosen then the gas actually breathed calculated for CNS and Deco.
With the Inspiration the lungs can be washed through quickly insitu. I unscrew the hoses leaving one attached to the scrubber to seal against the elements. The set is hung up to drain and the scrubber taken to my hotel or cabin to dry out over night.
I find the latter protocol simpler to follow.
The depth limit on the Dolphin was nitrox limited to 40m whereas the Inspiration can go far deeper with trimix or a simple heliair mix than I ever expect to go! ( I mix a 10/50 heliair in my garage without needing to be O2 clean).
My preference is for the CCR route rather than SCCR in the form of the Dolphin. You should note here that these are the only two rebreathers I have personally used.
I'll have a look for the Dolphin manual in my loft and if I can find it I'll let you know and send it on to you for a look at the maths/theory involved if you want.
Finally the Dolphin I used did not have an Oxyguage as standard so unless this has changed I would now insist on one being present to know exactly what I was breathing.
Regards Alan