I own a Zeos-branded NTC 6251EA v.6 with (most likely) grey alps.tw Type T5 clone switches. I've had to wait for a few parts to come in, so it wasn't until yesterday that I finished it. And the switches are really, really stiff. So much so that I thought they were binding. I even lubed a couple and there wasn't a change. Until I opened the feet. Now, the keys are still pretty darn stiff, but they don't feel like they're binding. Just bizarre. I can also say that the desoldered, pre-lube, switch felt absolutely fantastic in my hand and not stiff in the slightest. I've also found that if I put my chair all the way down and approach the keyboard almost flat, some of the stiffness starts to go away, too.
The other thing is that I had to replace some switches. The replacements are lubed white Alps from another Zeos 6251EA and feel as good mounted in the board as they did in my hand. My board is also extra, extra clean and had all of about a cotton ball's worth of dust when I got it. The keycaps, which are probably Tai-Hao TH-5539-5, are barely even very yellowed.
Any ideas, other than replacing all the switches with Alps orange or blue?