I've not tried the Double Four myself but
@pcake recently auditioned one at a TBer's place. Another TBer uses his Double Four in a ukulele orchestra. By all accounts the Double Four with its 4 inch drivers is a bit more musical than the BG-100 Bass Cub. Two different amps, really, with an outboard power supply on the DoubleFour. Someone here was / is (?) running a Bass Cub with (up to) three PB 100 powered bass cabs, and read here of one who plays the Vegas circuit with the Bass Cub and a PB 300 powered cab.
People who like the VT Bass
really like the VT Bass (and people who don't
really don't like it). By now I can hear the overdrive and compression at work, and learning how musical low character knob settings are. It helps to think of the character knob as a pre-EQ mids control. It adds a lot of depth to my PBJ, and I've been complimented for tone using it. Pushing the Ampeg BA-108 with the VT Bass is just plain old fun. I get Ampeg Plus out of an 8 inch driver that in all honesty is probably not top drawer
Every confidence the Vox VX50BA is much more than the sum of its parts. I can make no accounting for Vox' marketing strategy for bass. The little Vox stack kind of reminds me of seeing a VW Bug with a dune buggy body. Gonna be a lot of fun but you don't want to spend a lot of time in the overtake lane.
It's the Trace Elliot Transit B that might be a truly useful pedal
if you like the TE colour. I do. But it's really not an Ampeg tone and totally not a Phil Jones tone. It's its own thing, and a very fine thing. It seems to me a great grab 'n go pedal to put in the gig bag.