This gentlemen is a great supporter of the forum and a great fitter.
The argument is that you 'manage' all the sound rather than just let it mix with the HF improvement you get from more open fittings.
As with lots of this stuff, the answer is more 'it depends' rather than a straight YES/NO. Looking at the long term success of RIC fittings you have to examine why this type of fit has dominated the market in recent years vs. the more occluded styles if fitting. It's not just about the looks and slimmer wires, there's a good deal of subjective improvement in first fit 'sound quality'. Whilst RIC fittings definitely sound different from your normal hearing they seek to improve and ease the auditory resolution issues you're experiencing. This by and large results in greater fit satisfaction, happier clients and fewer returns.
So the World turns, and it becomes fairly obvious that although RIC are great for the majority of cases, there's some real issues:
Reverse sloping losses - Not a great fit as the resonance of the whole hearing aid is designed to provide lots of oomph at 3Khz and above.
Flat 40-50dB Conductive losses - Typical middle ear failures - All they really need is flat power and the wearers may be teenagers/young adults who prefer an IIC to be out of sight - see also cultural reasons and 70 year old men......
Power Losses/Leaky ears - fiddly moulds and receivers that don't like body fluids.
People with very limited manual dexterity/historical preference - The body of an ITE is easier to fit than a RIC, especially if you've been doing it for 30 years.
In terms of straight sound delivery, if you control the entire response of the aid from 50Hz to 10Khz, you can manage the noise by channel and turn down/manipulate the sound in the lower pitches as needed if they contain little in the way of speech information - you simply can't do that in a RIC. If there's a sound in the lower tones that 'masks' over the upper frequencies due to it's intensity - the RIC user has to live with it - the occluded user doesn't. However, this 'positive' in itself creates a portion of the 'artificial' sound associated with occluded fits before you even consider the occlusion effects from one's own skeletal sounds/voice. Rehabilitating a user requires much longer and more adjustment to obtain a satisfactory outcome that might never be as good as the RIC version of the fitting.
Full habituation with a RIC might be the 'cheap' and dirty answer - but there are some trade-offs as noted above. Making the correct decision on those trade-offs is why perhaps self-diagnosis isn't always the best answer AND turning hearing aid purchasing to a web delivery model is a bit of a can of worms.