The time factor is really the kicker that has kept me getting the GW trays so far. I don’t even have the time I need to paint my figures at the rate I want to use them, much less make anything fancy for movement trays. There was a time long ago, before family and such, but that isn’t likely to return until retirement now.
I do find the GW bases pretty cost effective for the most part when you consider that they look fair right out of the package, and I’ve seen some players do nothing more than a brown or black spray coat and that looks ok. I find it a bit tedious to sand and flock all the narrow parts, but with very little effort the GW bases can blend very well with your force.
My only real complaint about the GW bases is how “clean” the formations look. I don’t mind too much for well-disciplined armies but I’d prefer something more random for Orcs and such. Also, my Elves, Rohan, Dol Guldur, Isengard and Harad all have different looking bases on the individual models, and so I am compelled to have different movement trays for each army and THAT starts to get expensive. I can double-dip Elves and Dol Guldur, and also Rohan and Isengard, but then I can’t play those armies against each other.
I’m looking into making a basic base on MDF or such and using magnets on the models but probably won’t be testing that out for a while (other priorities). I want to see if I can create a few staggered patterns so that the models look more realistic in their collection. I think without the beveled edges of the GW bases you will get enough surface area to add some variation to the model positions. This won’t be as obvious for cavalry models but I think it will make a difference for infantry. Of course, your models will have their bases standing on top of the movement tray which may not look as nice as having them recessed, but without infinite time and money options are limited.