Gotta Say, I Think the Lower Material Limits Are Better
It's way easier to get enough materials to upgrade TFs now (Rovio hasn't reduced the material output from nodes and mission - not yet anyway!), to the point that I've had no choice but to spend time converting materials to gems in the lab, and that in turn gives me enough gems to speed up the upgrades. I recently started using Goldbrick more, and before the material limit reduction, it was to the point where I always had enough coins for upgrades, but would run out of materials and gems, so I'd have to wait out upgrades while building my silo and gem collection for a few days. Now all it takes is one mission or two, and I suddenly have enough of both to finish an upgrade with gems and start a new one. It's just a question of using the high yield lab recipes correctly and doing things in the right order.