I loved my old guild, but sticking with it cost me pretty severely. I have over 4 million gp, but handily get killed in GA because I am behind in gear. I have 30 at g12 and 50 at g11 and I am facing people who probably always have 50+ g12 toons. I still need 144 Darth Traya shards and I am fighting 7* Traya's almost exclusively. I only got Revan the second time through because I had to concentrate on other things trying to get my guild over the T6 STR hump. We could never get past P1 in HSTR because our guild would not focus on getting JTR.
Once I switch, I earned my first Traya shards within 24 hours of switching. I went from a low 30 stars in TB to one are two stars off a full run. TW is what it is at this level, but my old guild was maybe 50% at best. Our raid times rotate between 12 PM, 3 PM, and 9 PM EST starting times. Communication is a million times better. Participation is a million times better. My old guild was only using the LINE app, and I had to set that up being only an officer and not the guild leader. Once you see how Discord is organized, you would never use LINE again.
When I joined my new guild, I only had probe droid unlocked because of the BH mission. Once I joined the new guild, I need just two TB's to get from 5* to 7*. The extra crystals and guild store currency make a huge difference, as does the HSTR gear.
If your concern is advancing, or just keeping your head above water in the game, join a HSTR guild ASAP.