That is so cool that you got to talk to Rex. I thought we might lose him for a second there since he started to play more and more ESP basses but now that he has the RXT, I hope he stays with Spector. He seemed to really like that Coda in the video.
Did you tune the E string of your Rex Pro down to C with the .105? I have the stock Spector strings on my Euro 5LX but I am not sure what gauge the E string is since the Spector site says the 5 string tapered sets are 45-130.
My daughter asked me to play along to a few Disturbed songs and I tuned down to D flat with my E string and it was still very much playable and not floppy at all. I only kept it like that for one song though as I don't want to mess up my neck or anything since it's not setup for that. On a side note for Disturbed, 3 songs on the first cd each had a different tuning which was super annoying
My plan is to get a 35" scale Euro 4LX but for now, I will just tune the EADG strings down for songs that are too tough to play on the 5 string. I try to play them with the BEADG tuning and can play a good amount of the C# or C standard ones but when they start doing a bunch of open string stuff, it's a bit rough fretting every note.