This article made me a little saddened to read, but it was certainly no surprise. Lexus (most recently of course the RCF) seems to get bashed in many auto enthusiast groups, and while a lot of it is just the typical internet trolling, some valid points are made as well (just some) just like some valid points have been made in this thread.
I will say that personally, after recently having the opportunity to bring home a few German cars, there is one thing for sure that they all have had, which I really wish Lexus sports models had:
more torque. I've had the pleasure of bringing home the C400 4 MATIC (329HP, 354 LB-FT), 435i M-Sport (300HP, 300 LB-FT), A6 w/S Line (333HP, 325 LB-FT), and most very recently, a surprisingly fun VW GTI (220 HP, 258 LB-FT)-- I know that last one isn't a luxury car, but it's still a German car and had a lot of torque, relatively speaking and even though it has much lower HP than the others I've mentioned, that torque combined with the turbo made it a real blast to drive.
Up until recently, I've really only experienced Lexus models (I mean, for more than just a little test drive around the block) and so I never thought anything of the other cars out there. I grew up in a Japanese import only household and never knew what the German cars had to offer, but always heard horror stories about high costs to maintain them (this was a long time ago). But now that I've had the pleasure of driving a few German cars for extended periods of time, I will say that the main component of that experience which really makes a difference to me is that torque-- just the way the cars feel when you accelerate and it just pulls you forward, particularly in the Sport modes.
However, with that said, there are many things that Lexus offers and/or does better than the German competitors-- I find the Lexus interiors are more upscale and luxurious looking/feeling, whereas the BMW and Audi in particular, have much plainer interiors [I'm speaking from personal experience in models that are A6/5 Series level and down; go upwards and you're definitely getting into nicer interiors across the board] and from what I can tell, generally speaking, the Lexus models have more features in them standard-- such as push start/keyless entry or EC Inner mirror w/GDO, whereas the German models I've looked at offer these items as extras.
Regarding the RCF and M4, I had the chance to drive both on the track at the Running of the Bulls event last year and I will say what I think others have already said-- the M4 is a great car to drive, no doubt about it- However, it felt really easy to lose control in it. The RCF felt quick, sporty and confident on the track, and I never once felt that I would lose control, even at high speeds.
I personally won't be taking my car to the track, so for me, the RCF is a fine balance of power, comfort and styling, and at a price point where I get the features I expect in a luxury car without breaking my wallet.
I guess at the end of the day, as a car enthusiast- I can find happiness in driving most sports cars out there, regardless of whether they are Japanese, German, American, Italian, etc. If I had an infinite steady flow of cash, I'd have a whole fleet of all different brands of cars in my garage.
For now though, I find the balance I'm looking for in the Lexus models I've had and will continue to own in the future. And I'm used to getting trolled online for it, without taking it too seriously