Most compact/travel-friendly CCR - Sidewinder, Optima CH or ??

[Mobulai]

the FX-CCR as another alternative

The xccr (aka FX, subgravity) option is great as well — their clicking connections are very stable and make predive preps/checks smoother (no real experience except from casually messing about with it once at Boot and watching friends at the diveshop)
Another advantage is a wider network as XCCR is the EU face and their partnership with subgravity brings it to the US); can’t say the same for the choptima

 

[foxdude]

hey the iqsub fx-ccr is quite compact and easy to carry and use. It's a chest mount so you can use it with any setup sm/bm/doubles whatever. I love mine which is my first ccr and I have it for about 7 months now. Everything is easy to access and infront of you (mav/o2). Procedures are easy and you can actually unclip it underwater if you need to check for bubles or insect anything which is not hard at all.

 

[justinthedeeps]

I got on an FX-CCR recently. It's covering a lot of bases in this category responsibly, with advantages extending from an existing well designed platform (XCCR).

Haven't tried much belly-to-ground macro photography yet, but I'm not that often a lay on the ground kind of photographer either (TBD...)

Back mount CCRs handle moisture better. Except to see more moisture settling down into the CM and SM units (including the head) vs back mount, regardless of the marketing or design characteristics (basic physics wins). A head and sensor flood, or a more cryptic sensor block, is absolutely more likely on these units versus a well designed back mount CCR. CM and SM CCR divers should be trained to monitor and recognize the possibility of water-blocked sensors, which could give stuck, unresponsive, or erroneous ppO2 readings.

O2ptima CM might have a slightly more forgiving WOB given the special counterlung orientation(?) But some people with shorter torsos feel it ends up too long as a result.