TBH, the debate about Leica R lenses has gone on for decades and it seems pointless to re-prosecute the case either way. I've owned quite a few leica R lenses and bodies over the years, and still do, although I use the leica lenses on mirrorless digital bodies rather than film these days. The most notable mistake that I think people make when starting to consider leica R lenses is failing to study them. The R lenses span from the 1960s to 1990s and the differences between them are dramatic yet they tend to be grouped together and discussed as though all R lenses are equally good or equally bad. Study the lenses and you will understand why some are mediocre (and cheap) and some are still considered about as good as they get (and are expensive). But don't assume they are all the same standard, they are not. Some people buy a relatively cheap Leica R lens (typically early lenses) and complain about the performance, usually with high expectations, but they often don't appreciate that they may have purchased an early lens which may not have a good reputation anyway. Leica wasn't great at wide angle lenses in the early days but this changed in the 80s-90s.
My experience is with the following lenses ;
2.8/24, great colour and stopped down sharpness but an old design so not up to modern standards for edge sharpness, but still a wonderful lens and one I love to use. The lens hood is superb!
2.8/28E55, still considered one of the sharpest 28 mm lenses
1.4/35, a great lens, I love the rendering and wide open sharpness, it's actually worth the money IMHO
2/50E55, I dislike this lens because of its significant wide open purple fringing which prevents it's wide open use in the first place. It has harsh bokeh too. Others love it, it's very sharp across the frame so is a great 'landscape' lens. It's one of my sharpest lenses when stopped down but apart from that I don't see any point in having it. I prefer fast lenses so don't use an F2 50mm lens at all.
1.4/50E60, I'm not sure this one is worth the exorbitant money asked for it today, although it is an excellent lens, but in high demand by video people which seems to have driven up the price
1.4/80, this is my favourite people lens, it's worth the money and I would certainly replace it (even at todays prices) if I had to. Wide open sharpness is excellent in central area.
3.4/180, sharp, but too slow IMHO. Not sure why I still have it TBH.
2/180, this is a stunning performer, it's sharper wide open than many lenses stopped down, worth the money and the 2.5kg you have to lug around.
2.8/70-200 (a loaner I had for a few months) I remember it being very sharp but so are most modern zooms
I recently sold an R8 and kept an R4 and RE. The R4 has a bad reputation because of early electronic problems but if it's working now then you can be sure the electronics have already been repaired. I happen to prefer the R4 over other bodies because it has a larger viewfinder magnification which makes it easier to focus wide angle lenses more accurately. The original focusing screen needs to be replaced with one from later models which is much brighter. I love my R4 and the RE is certainly a decent camera too.