Richard,
FoxPro Advisor has run several articles trying to explain frameworks and their benefits, but to date I don't think they have had a product comparison. I did my own research earlier this year and picked the Mere Mortals Framework. It has been around for several years, has great documentation and they issue updates throughout the year. So far it has exceeded my expectations and definately improved my application development efforts. Check the Third Party section of UT files for more info.
Kind Regards,
Mat Kennedy
Decision Support Technology Inc.