^
of course he's gonna say that he prefers the rings that he sells...
I truly have tried to be objective, although clearly there is a reason for anyone to suspect bias. Of course, anyone can do a comparison for himself. The effect of the rings is similar between a Type-S HHKB and DIY-silenced HHKB, but I have noticed on my Type-S that the silencing seems not quite as even across the board as I have gotten with DIY silencing. I have not been able to do a comparison between a factory-silenced RF87U and DIY-silenced RF87U because I do not have a factory-silenced model, but I can say that silencing produces dramatic results. The before and after is the most dramatic on the CM Novatouch.
In fact, as others have discovered, there is a major improvement to be realized in Topre-switch keyboards by lubing the stabilizers and sliders. I have recently gotten the best results using Superlube 51010 oil. I apply it sparingly to just the slider rails using a small paintbrush. I do not put oil on the cylindrical part of the slider or switch housing. I also lubricate the plastic and metal contact points in the stabilzers. Finally, I have found that the spacebar sound can be deadened by placing self-adhesive squares of anti-skid foam rubber strips on top of the plate under the spacebar on each side of the spacebar switch.
So, for the best overall silencing, either install silencing rings or start with a Type-S, but also lube the stabilizers and switches and consider putting shock absorbers under the spacebar as well.
I can also be found to have stated numerous times in the past that I prefer Hypersphere rings over the Type-S, and I
don't sell them

For me, pricing is important. I don't find the Type-S to be worth the cost, when Landing Pads and Hypersphere rings are an option. I had a Type-S for a long time, and just didn't ever love it. And for me to keep a $300+ keyboard, I have to LOVE it. Mine had whistling issues and generally wasn't great.
I also had silenced Pro's/Pro 2's with Hypersphere rings and EK Pads to compare. THe EK Pads can work quite well, but they take a ton of time and effort to get perfect. Ironing them, making sure they are all even, and trimming them can take hours for an HHKB, I wouldn't have the time to even consider using them on a RF. In the end, they do sound/feel pretty good. Hypersphere rings, while a bit pricier, are a better option than the EK Pads and the Type S IMO. They feel great, sound great, and generally get the job done.
Also, as Hypershere mentioned, there are benefits to DIY silencing as well. I also lube all of my Topre boards, so I end up having to take them apart anyways, meaning I might as well DIY silence them while I'm at it and save some money.