The timing of this question could not have been better. I just finished my CCR rebreather training Sat, still dog tired. When I signed up for the class, it was to get certified for the Optima, and then changed over to the Inspiration on the 3rd day. The optima was used by one individual each day.
First let me say, that the instructor (Jeff Bozanic) did not say anything about either unit, in any way, to influence my decision. He was neutral (frustratingly so), and would not offer any opinion one-way or the other. He would not recommend or even make 1-1 comparisons. This decision was strictly mine, based on what I learned, what I saw and my perceptions of my skills now and in the future. There are pro's and con's to every system out there, and I definitely came away with very strong opinions of some units, the challenge however is to determine what is best for you. I am 6'5", 250+, basically a big guy. I am not as limber as I once was and after diving for over 26 years, I certainly don't qualify as young. I do however have a substantial amount of training and experience. Those are some of factors that influenced my decision.
I hope to write a long review of the class in this forum or finally join rebreatherworld and put it there. Since I don't want hijack this thread that will have to wait.
There are many fine units out there, but I'll just stick to the question Optima or Inspiration (or Evolution, a smaller version of the inspiration).
My decision to change started when I inspected the Optima unit and saw the construction and materials. There was a big difference in the quality; the optima is exactly what it professes to be a very low cost CCR; the inspiration is a very solid mature design. The optima disassembles very nicely, and is easy to clean (I did it several times), when compared to Inspiration. It is really easy to assemble, especially just sliding in the extend air cartridge. It easily takes less then half the time to set up. And to clean it the parts needing disinfecting come off quick allowing you to get somewhere warm to do your cleaning, plus it takes up less room. That can be important. I really liked that I could use my own harness/BC rig. There are many things I like about the Optima and it appears to be a very capable unit hence my signing up to take the class.
However, there are some things I really did not like. While I finally got over the lack of being able to use granules, some things I just had a problem with.
1) The hoses are a smaller diameter. I think the work of breathing is increased as a result.
2) Hose connections are cheesy in my opinion, one caution they pull off easy; yes underwater; not a good thing.
3) Getting to the head to inspect it, or changing out components is a pain in the @$$.
4) Screwing on the DIVA (HUD) daily is asking to lose the screws
5) The on/off switch for the handsets is installing or removing the battery. Other threads have talked about the short life of the batteries (plus side though- they are just AA, a set of rechargables that you treat like camera batteries was my plan). But opening up the handset between dives on a wet boat did not seem wise to me.
6) The case/cover came lose while diving causing drag and looked sloppy to me.
7) It leaked a lot, though surprisingly it had very little water in it at the end of the day (~4hrs a day on it). No under normal circumstances it would not pass the bubble test at all; long story as to why it was dived.
8) We took more in weight for the extendairs for one Optima then we did in granules (total) for 3 inspirations.
9) Overall quality, the inspiration is just made the optima look cheap.
Out of scope so minimal info- I also looked at the Prism and KISS systems, and dismissed them for other reasons.
If you have specific questions about either unit I'll provide my opinion.
my 2 psi.