Funny you should ask this.
I was just researching the Kailh Deep Sea a little bit last night.
Apparently, they are probably comparable to the Kailh Fried Egg silent switches. They seem to use the same recent housing design and dampening method, and spring weight may be similar.
I just ordered samples of Fried Egg to evaluate. When looking at the comments in Youtube videos featuring these two switches, commentators were sometimes asked if these felt ‘mushy’ as other silent switches.
The video producers in one or two instances claimed that these new Kailh designs, can’t remember which of the two, did not feel as mushy as other silents. That even OUTEMU Bobagum felt mushy by comparison. But that is a very small sample.
I personally doubt that these Kailh switches will offer much new, but I ordered some because they are affordable. I also ordered something called a “Kailh MX Silent tactile:”
They were only $9 CAD to have 10 delivered. It could be identical to Kailh BOX Silent Brown for all I know, but the stem looks different and the spring weight may be a little less.
Advice regarding the Fried Egg and Deep Sea switches was somewhat varied. Some people lubed theirs by applying generous 205g0 to the upper housing guide-rails. However, others found that to reduce the “rubber-dome” sound of the stock switch. Personally, the sound seemed “wetter” after lube, to my ears.
Right now, I’m typing on a recently-completed IKKI68 Aurora. I’m using a custom switch of OUTEMU Silent Sky stems inside Cherry MX Clear housings. Springs are lubed 60 G 14mm TX, the switches are lubed with 3204 and filmed with TX films.
These are easily the best MX-compatible silent tactiles I have ever used. They basically sound and feel like silenced EC switches, maybe about 30-40 G by those measurements. Very crisp and bouncy and responsive. I’m using thick Cherry PBT with these to dampen the sound.
Stock Silent Skies are very problematic. The housing is not sized properly, they are very noisy, wobble is insane, and it is a lube-starved switch. But once you take the Silent Sky stems and put them in another housing, they can be very good and are very underrated.