There are many 3rd party companies offering these crco solutions, so it seems there is a big market for them. Last year I believe straumann started offering them in their cad software, which is an interesting move on their part. I had a conversation with the late Mark Jackson about this a few years ago, he pointed out about the galvanic reactions, as a result I've never tried. Perhaps in the next few years there'll be more clinical data available. I stick to Ti base or gold ucla's for peace of mind.
I have limited knowledge on CrCo. When I ask dentist and labs for their opinions I receive conflicting information (largely depending on what they have read and seldomly on their personal experience using it) in the USA.
The advantages I have heard from clients are - 1. they want to cast but gold is too expensive and all plastic abutments cast imperfectly so they can cast with a chrome cobalt abutment because it has a machined interface. 2. we have a chrome cobalt premilled blank and labs with milling capabilities want to stack porcelain directly to a chrome cobalt abutment because they can't stack directly to a titanium premill so it saves time and money (versus casting again).
The cons are- 1. supposedly incompatbility between chrome cobalt abutment and titanium implants 2. galvanic reaction 3. oxidation issues
The prices are more for chrome cobalt abutments than my ti base but that may be because of our pricing and I am unsure of the rest of the market.