As a PJB owner, I'd suggest the Cub and Double 4 are only really suitable for home use. They're lovely little amps - clean, excellent tone. I compared and tried both recently as I fancied something compact for low volume practice, but decided to stick with using a lightweight head and one of my PJB cabs, which is only a twelve inch cube, for the purpose. Yes, there are reviews saying you can gig with Bass Cubs, but you would be limited to very quiet wine bar jazz combo type gigs without a drummer. Both it and the Double 4 are very limited in output. Given that the Session 77 is cheaper than both of them, I'd go for that. It has the same preamp, is a bit more gig-worthy (although still not for anything that needs any serious volume), you can add extra power amps/cabs to it if you do need more power and it's still very compact/portable. Hope this helps.