I agree+ Macs keep their value very well, where PCs loose it badly.
Point is that there is almost no reason to buy new i9 model (which is really expensive) and only people who sleep on $ can "easily" justify it. It's because this i9 will never get into its possible turbo modes (eg above 4.2GHz) due to being installed into laptop which will never deliver enough cooling power. i7 is about same CPU and it can also go to 4.3GHz (which will be most likely also never achieved). At the end both CPUs will at best work at around 4GHz, so because they are almost the same CPUs they will deliver same real word experience.
i9 in MacBook is basically in 95% just a pr thing which generates money and keeps brand prestige.
Based on values found on the net:
i9 at its full potential can hit almost 1400 in CineBench test. In Mac it hits around 950 (with Apple fix), so this is about 30% worse than it could be.
i7 can do about 1300 when properly cooled, in Mac is does about 1050 (with Apple fix). This is also about 15% worse than in Dell XPS.
I could not find better value for i9 model, so for long test it's actually slower than i7 (so what on earth am I paying almost 300£ extra for?). For whatever reason i7 can "easier" maintain higher frequency over long times, so at the end it's actually faster in Macs.
Looks like Apple needs to properly tweak i9 as there is no reason why it should be slower. If anything it should be the same (and faster for peak moments where eg. only 1 or 2 cores are used). Looks like Apple done poor job and "code" for i9 is not really tweaked properly at all. Their quick fix for initial/embarrassing result is good, but in the same time i9 based machine is still very disappointing.
What is interesting that many review websites actually focus on i9 model and don't even show/compare it against i7. We know why and most likely who is behind it
This includes new test by Dave Lee, which are very "vague" and sounds like Apple censored. Poor world of corporates influence.