My guild has been affected by STR as well. We were not one of the top guilds which collected the strongest players from next tier...so we were one of the feeder guilds. Fortunately most of our members remained and are holding their heads high while mentoring the not quite ready for heroic portion of the guild. We don't have Traya and we don't have G12.5 pieces and we are increasingly less relevant in our arena shards - but their is some honour there and we are having as much fun as the day before this stuff dropped.
It feels like one of the goals was to move players into distinct tiers - the very best players will be playing Heroic and facing each other in TWs. This has a positive effect on the lower tiers of TWs, we don't see 10 ridiculous players (and scrubs) building a wall that can't be bested by a guild of 50 relatively equal players amounting to the same GP.
It is unfortunate that the STR is a bit of a slog for some guilds who aren't at heroic yet- but if they are gearing the right teams, watching videos, and sharing strategies they will keep moving up ranks.
The T6 was a slog for us until about 2 weeks ago, now it's cake...and heroic is waiting for us this weekend - and it feels really good. I regret nothing.
I am glad that this content has taken some time. If everything were easy and beatable day one I would just be playing this game to click JOIN and SIM, may as well be playing Adventure Capitalist...
...so...frustrations noted...it's worth it to find a group of like powered individuals and dig in wherever you are to get better.