I looked up that Forbid F4 and I don't like what the warnings say about it.
It say's:
Do not use on vegetable gardens
Do not use on plants intended for use as feed or forage
Not for use in commercial greenhouses or nurseries, or on fruit or nut trees
If on skin or clothing:
Take off contaminated clothing
Rinse skin immediately with plenty of water for 15 to 20 minutes
Call poison control center or doctor for treatment advice
Also say's Do not apply more than 3 times per season.
http://www.cdms.net/LDat/ld6P7000.pdf
I don't think I would want that on my plant's no matter how well it works.
Spinosad on the other hand is use to treat head lice on humans and fleas on dogs and cats. The only real danger to using it is getting it in your eye's or mouth. It is rated slightly toxic.
I am ok with multiple applications to get rid of a pest versus wearing a respirator and hazmat suit to apply something that I would never want one of my patients or myself smoking. Besides, you can spray it as close as 2 weeks prior to harvest because we all know spider mites can show up at any time during the grow, not just in the veg period.