I did it, and it's changed my life. I was a class teacher, primary, over 20 years experience. I worked 4 days a week, but ALL day on my day 'off', most evenings and Sunday afternoon was spent planning, assessing and marking, and a good chunk of the holidays.
I am now an HLTA, paid on the top of the scale, and even with pro rata taken into account I earn more per hour than I did as a teacher.... This is helped by the fact that I work 5 days with 3 afternoons paid as a teacher (I'm a PE specialist and cover 3 afternoons PPA teaching PE) but I just work 8.30-3.45, no meetings, no parents evenings, no IEPS, no classroom environment to maintain, no data or pupil progress, relatively little planning (which I get done in the1.5 hour PPA that I get each week in school) and the rest of my time is spent teaching small groups English and Maths, withdrawn from the class, but following the class teachers planning, and doing guided reading, phonics and small group interventions. I adapt and annotate planning as I go and mark as I teach.They are happy with this. They get an experienced teacher doing an TA's job and I get a life back.
I take home about 3/5 of the wage I did as a class teacher, but work about 2/5 of the hours, and that's just during a term time week. I will have no work to do in the holidays. They will be family time proper. We are lucky that we could afford to take the hit on our finances, but family life, my stress levels and the time I can spend with my children is so MASSIVELY improved, that we feel it is worth it. I do worry about my pension. But I also don't think this job is my forever job - it's a break and a rest and restore while I consider my options. And in the meantime I'm loving it.