I finally bought myself a Cherry G80-3000LQCDE-2 (Q = Clears, DE = German, 2 = black) from PC-Planet, €59.87 shipped from Germany to the UK. This is the only model in ISO layout. I'm going to focus just on the switches, not the G80-3000 range.
I've been using it at work all day for a couple of weeks now.
Clears are a cross between linear and tactile. They do have the sponginess about them of linear switches, in that even after passing the tactile point, they don't bottom out, as the springs are very stiff. The advantage for a heavy typist is that you don't bottom them out hard (which is fatiguing if you do, so you learn not to) because they absorb the force of the stroke nicely, without having the jarring tactile point and rapid drop of ALPS. Being PCB mounted helps here too; I don't have a G80-3000 with blues or browns for comparison on bottoming out.
I think I can echo the general sentiment that that they're insufficiently tactile. Most people say that clears are too stiff and insufficiently tactile. I've always wanted that perfect balance between ineffectual featherweight (MX browns) and violent heavyweight (ALPS) switches: a tactile point that's smooth instead of sharp, and enough meatiness in the spring that you can put some feeling into the keystrokes without bottoming out hard. I don't know that making clears lighter necessarily help in my case – they counterbalance heavier strokes nicely. My complaint is simply that the force curve of all Cherry switches is linear, with a notifying hump in the tactile variants.
That said, I don't have a problem with the lower resistance in a Topre Realforce variable, as the lower resistance 45 g domes is offset by the top-heavy force curve. The Realforce variable is an exceptional keyboard. It would be interesting to compare—if it existed!—a 55/45 variable instead of 45/35 (for some reason the only 55 g key in the variable is Esc, which seems pointless).
As for clears, I find the G30-8000 to be a pretty usable keyboard. Not a patch on even a cheap Dell KB1421 for feel, yet I can use it for hours and hours with the only complaint being the sponginess of the linear force curve bothering me occasionally. (I don't have a problem with the Cherry stabilisers either. I can't even sense a difference honestly.)
It's a viable alternative for anyone who wants something that's much harder to bottom out than normal Cherry switches, but that is relatively quiet compared to buckling spring or ALPS.