I'm new around here, so my opinion might not carry much weight, but I've read through this recent thread:
https://geekhack.org/index.php?topic=70636.0 I think it's quite useful for new starters.
As you can see, topre shows up a lot in that thread, and from what I read on the forums so far it seems the Realforce 87u is the daily driver or the only keyboard for quite a few users (the 55g uniform seems to get a lot of love especially). You might want to try that next as an alternative TKL option.
Just my two cents.
EDIT: As for the sturdiness, you might be surprised but, contrary to the popular opinion, I don't find a Filcos to be very sturdy (especially not the full size ones, the TKL are always better though). It gives a sense of sturdiness when you type on it, yes, but when you pick up the whole case in your hand you can feel the plastic bending a bit around the plate. The sturdiest keyboard I've held in my hand is the Deck Hassium Pro, but that keyboard has its own problems. At least the one I got has some noticeable difference in switch weight between alphas and the numpad, and the shift keys feel somehow sticky (could probably be fixed by lubing the switches). The second sturdiest keyboard I've held was probably Ducky G2 Pro and after that a Filco. I have not held any full metal cases yet. In a smaller format, I think the Leopold FC660C is hard to beat in sturdiness out of the box.