I’ve had both CIC/ITC (I’m not sure which they are, but pretty small) and RIC, and for me there is no comparison - I can’t imagine ever going back to completely in the ear.
When I got my first hearing aids I was in my early 40’s, and was adamant that I wanted an in the ear style because I thought they would be less noticeable. I found them ‘ok’ but I really didn’t have any idea what they should be like. I was definitely hearing sounds that I could not hear without them, my family and co workers could tell the difference immediately, and they did help in a lot of situations. However, there were also a lot of situations where I actually felt that I would be able to hear better and clearer if I didn’t have them in. I mainly felt this way in noisy places, like trying to order in a cafeteria. I also felt very occluded - like my ears were plugged a lot of the time, and no amount of adjusting them (or remaking them even) seemed to help. But I continued to wear them and when I decided to get a new set last year (about 6 years later) I had every intention of going the same route.
However, the one thing that I didn’t like about the ones I had was that there was no connectivity (which was pretty standard at the time) so I couldn’t change the volume or program without the remote. The remote was another device that I had to remember to charge and carry around, so I was hoping a new pair with improved technology would be able to connect to my phone. I wasn’t concerned about streaming, but I was hoping to be able to at least adjust volume (they are too small for buttons). The problem was that in order to get that connectivity, you need an antenna, which on the brands I looked at was very noticeable. My audi said that with my shoulder length hair behind the ear would actually be less visible. I wasn’t sure I believed that, but decided to do a trial. I trialed the oticon Moores, and could not believe the difference - SOO much better! They are way more comfortable - not necessarily more physically comfortable but because I don’t have the ‘stuffed up’ feeling I don’t even notice I am wearing them - I have even gotten in bed and the shower forgetting I have them in, which NEVER happened with my old ones. I also don’t have any situations where I think I would hear better without them. I think that may be because my hearing is still reasonably good, and the RIC HAs ‘aid’ my hearing, instead of blocking my ear and then replacing my hearing if that makes sense. I also find the streaming capability convenient for listening to podcasts or music, even though it wasn’t necessarily something I was looking for. My Moores are a different manufacturer and are about 6 years newer technology so maybe the drastic improvement for me is not totally attributable to the style, but I do think the style has a lot to do with it. However, it will also depend on your loss as well.