OK @Kevin_Anthony, GeckoTek plate arrived today. I was pretty excited to give it a go as I have a very large square print that has been warping on just about every try with other means.
I was under the impression that the GeckoTek plate was magnetized, but that proved to be a pipe-dream (it might be a little bit, but on the smooth Flux build plate it moves around like a drunken sailor). So I first tried to lock it down with small magnets. BIG MISTAKE!! The head just kept being attracted to the magnets and at one point, the whole plate slipped in one corner and lodged itself on top of some of the magnets, causing the extruder to scrape a not so nice line in the surface before I could stop it.
In the end, I settled on old fashioned sticky tape:
The scrapes I made does not seam to have made too much of a lasting problem and thankfully are at the very extremes of the build. I'm a little annoyed that I have to tape it down every time, so I think I'll reserve its use for difficult prints.
Overall, I'll give it 4 (EDIT: 3.5, EDIT2: 3) out of 5 stars.
No warping (EDIT: limited warping, EDIT2: some warping)
Calibration works flawlessly
Have to stick it down with tape
PS: The print I have in progress has quite a few hours to go, so I can't say how easy it is to remove a print yet. If it turns out to be a problem, then I'll post an update.
EDIT: 3 hours in and some minor warping is beginning to show:
The least warps I've had on this print, but still somewhat disappointing .
4 hours in and this happens:
Now really disappointed. Probably still OK for smaller prints, but this is no better than glue-stick