Hi Toril, I too use both USB sockets but I always keep the USB stick in the back socket plugged in, I make sure it is there when I switch on and I use it as my main drive, all my own styles, voices and registrations are stored on it and linked together in one single place. I use the front USB socket for my 2nd USB where I have stored all the various styles etc. I have downloaded from this forum and other places, but I only plug it in when I need it for something. Anything on this 2nd USB I want to use is copied into my USER area while I work on it and then moved onto the 1st USB. The original is still on my USB 2 if I want to go back to it and start again because I've made a mess of my editing.
This system works well for me because it means I can easily back up my main USB(1) by inserting it into my laptop, make another copy of it if I want, also take it out with me to use in friend's keyboards without having to take all my gear and everything still works together because it is all in one place.
If something goes wrong with my keyboard and I can't access my hard drive or user drive I don't lose my work.
Just recently I swopped my T5 61 for a T5 76 and all I had to think about with the hard drive was re-loading expansion voices, everything else is just read from USBs.
HOWEVER, as other people have also pointed out, when I switch on the keyboard I need to make sure my 2nd USB isn't plugged in at the front otherwise the keyboard recognises that as USB1 and links from the USB at the back won't work properly. If I do that by mistake the only thing to do is switch off, take out the front USB and switch on again.
That's how I work anyway, glad you are enjoying the T5, i love it, Happy Christmas!
Pam