Every single CB currently being manufactured and manufactured in the past can manage 12dB SINAD or more at -120dBm. Why is that important?
Well it so happens that -120dBm is about the same level as galactic noise on the 11m band (actually its a couple of dBm lower than the noise floor) so no matter where you are on planet earth then if you're running an antenna with at least unity gain (0dBi), the noise floor will be higher than -120dBm. 12dB SINAD is the signal to noise level where speech is perfectly intelligible and on FM would be clear with just a slight hint of white noise behind it.
The only time it matters how well a radio hears below -120dBm matters is if you're using a crappy antenna which is so bad it can't even manage unity gain and you should be concentrating on improving your antenna system and not trying to find the holy grail of a radio with a receiver that can compensate for the loss. However consider that even the best HF amateur radios can only hear around 10dB below that level without pre-amps. My Flex 6500 is around -128dBm from memory but its not an issue because the noise floor is always higher.
The commonly heard claim of "new radios don't outperform old favourites" doesn't pass scrutiny once you hook them up to a proper radio tester and start doing some measuring and the claims are usually based on S meter readings from CBs which have far from linear S meters, which are very rarely properly calibrated and usually done by Bob listening to Fred a few miles away and comparing what he gets to Fred or even worse by Bob listening to Gunter in Germany via skip. Any judgements based on S meter readings not only from one make to another but from one identical radio to the next is pointless with CBs. Old radios sell better than new ones because people believe urban legend about performance like all the crap that's banded about around CB vertical antennas when the reality is that for the vast majority of cases where there's a large difference its pretty much always something to do with the antenna installation from one place to another that shows up the large differences claimed.
I would like to say that like most, if not all on here who have been into CB/amateur radio for any length of time I've burned a lot of money chasing the holy grail of a CB/amateur radio that can hear stuff no other one can, mostly because of the antennas I was running. As a ham I went through several different radios before realising there is no such thing as a magical radio that can hear stuff none of the others can.
Eventually partly through researching about noise and from getting a Marconi 2955 and shoving loads of radios on it and doing testing I finally saw the light and that sensitivity is not the thing you should be basing purchase of a new radio on as they are all more than capable of hearing well below the noise floor. Even the Commtron CB40F which had a serious reputation in the UK of being completely and utterly deaf in the 80s turned out not to be when I put one on the 2955. It easily managed 12dB SINAD at -120dBm and its reputation was based entirely around the fact that it was impossible to calibrate the S meter properly and even wide open with the pot for the S meter the universal CB S9 level of 100uV would only get you a S7. Therefore everyone thought they were deaf because they had a seriously stingy S meter.
Same happens nowadays, people basing opinion on S meters. I've seen plenty of people say the Grant 2 and Lincoln 2 have poor ears yet I've watched plenty of m0ogy's videos on Youtube where his Grant 2 and Lincoln 2 are hearing stations quite clearly but showing S0 on the meter. I'd say it was poor S meter calibration on those two radios rather than the receiver not being sensitive enough.
In fact when you look at amateur radio the manufacturers know this is the case. IARU/Collins standard is 6dB per S point. Current generations, especially Icom and Yaesu, have S meters that tend to be calibrated at a S point = 3dB up to S9 then 6dB per S point above S9 so the needle swings more and keeps the owner happy. This makes a radio like my TS480 appear deaf in comparison as the S meter isn't calibrated like that and putting a -100dBm signal into my TS480 would result in signal a few S points down from the FT950 I had.
Radios should be selected primarily on two things, neither of which have anything to do with sensitivity:
1) Ergonomics. If the screen is too small to see, the controls too fiddly to use (Ranger 2950 putting the mike socket below the channel selector for example) and the layout or menu layout makes no sense (Yaesu FT857/897) to you then you're not going to enjoy using it no matter how good it is.
2) Selectivity - the ability to hear weak signals next to strong ones.
