I've not A/B'd them and pair the Little Bastard with a newish EICH 15 ported cab. The Spyder/B15N w/JBL combo character is "chocolatey"/ warm and rich, bringing a specific tube-y JBL sound/tone. This is partially due to the Spyder having a two tube pre and of course the vintage JBL speaker. The Little Bastard is all tube and 30watts with simpler controls. There are some overlaps, but the Spyder has Volume & Gain, whereas the LB has only Volume. So the LB w/EICH 15 cab in comparison is very neutral. It has a nice tube sound but the EICH (cab/speaker) doesn't have an overpowering 'character'. The EICH has an adjustable tweeter which is different from the B15N. (both are ported) I've yet to record using the LB/EICH but I suspect it would be a perfect rig for clean recording. TSC will be recording four original songs before the year is up and I'll be bringing it that day.
In summery, I feel the LB on my B15N cab would probably sound similar to the cab with its '76 Porta-Flex head. Eventually I'll do an A/B on them.