First off, thanks for any help anyone may be able to offer.
I finally successfully upgraded from stock FW to Gargoyle 1.7.1 after I figured out (duh) that an overwrite of the protection function on factory firmware was required first (at least I think that's what I figured out!). Here's a good link for that - https://forum.openwrt.org/viewtopic.php?id=61389
Anyway, after two FW flashes, one to allow me to get custom FW on the router, and another following the installation advice on this site its working. So I'm happily at 1.7.1. However I don't see my 5GHz radio and can't connect using wireless N.
I'd like to upgrade to 1.9.0. Any advice? I'd like to be as safe as possible so I avoid bricking my brand new router.
Lastly, the reason I got this router and am really hopeful about the feature set of Gargoyle is bandwidth throttling. We're a big family (the wife and five kids) and we have more Internet devices than you can shake a stick at. So any advice about how to be sure bandwidth and latency (for online gaming) are configured would also be GREATLY appreciated!

Thanks!