the valveking is a new line for peavey, they have only been out a week or so, so i can't comment on them other than the fact that it is tube and cheap.
for the cube i would rate it pertty high, the amp modelings didn't sound like they were suppose to but it didn't matter too much because even though they different they sounded good. The cube is loud as well. I played the little battery powered one and i was impressed with how much sound it could put out without seeming stressed. So i would rate it about a 9
the spider .
It has all the effects and modeling crap, that isn't so much as important as quality of the effects and sound. I felt it lacked gain, what gain it did have was weak, and not a full sound , it all seemed too processed . The effects were sort of cheesy, again they sounded too processed and not natuaral. rating of about a 5
The vox valvetronics
these have extermly high quality effects in my opion they just lack in gain/amp modeling . like i said if you had a driver pedal in front of one they sound pertty good, plus you get all the high quality effects.
i would rate about 7.5
i maybe getting a valveking myself, i could use a more portable setup , plus with it being 50 watts i can power my cab with it as well . Peavey to me has some of the best stuff around for the money.