im doing my class 1 this week on a 121 4 hour basis strict but fair instructor but find it very intense and sweaty hands and my head hurts,im struggling on the reverse which lock to turn etc which im sure comes easy to some but not me(i admit im a bit slow) i did my class 2 on a 2-1 basis and found it more relaxed being able to watch the other driver and listen to the instructor, anyway be intresting to here what other peoples views are on which is best. oh although not a unit im having a practice with a caravan and transit later so if you see a caravan upside down it"ll 
probaly be me
I done my class 2 on a 1-2-1 basis and when I do my C+E eventually I will go back again. On the first day I had a pounding head ache but after the first day I was okay. I prefer 1-2-1 but I got on well with the instructor aswell so that helps.
I think it comes down to personal preference but its 1-2-1 for me
There’s no right or wrong, no better or worse. There’s pro’s and con’s to both.
Personally, I have a preference for 1-2-1 but there are endless perfectly credible arguments for both methods.
I’m sure your instructor will be sufficiently skilled to know when to “ease off” and do relatively simple stuff for a few minutes to give your head time to cool down!
All the best for the remainder of your training and good luck with your test.
Just as an afterthought; if you feel your instructor hasn’t realised you need an easy 5 minutes, try telling him! We’re good but we’re not mindreaders!!
thanks peter i didnt want to give the idea i was on here with a more drama than dallas pitty potty or a picky nicky whos best instructor list as you say it may suit some and some that dont, i fully admit i had a knock to my head when doing my think im barry sheene motorbike crash when i was younger resulting in im a bit slow at instructions which makes me feel thick and may give others that idea to, i wouldnt say im backwards(mind you might have helped with my reversing if i was ) anyway thank you for your kind words i shall keep you posted i must get some green wellys with full right lock then left lock painted on them before my instructor gets a big stick or bangs his head on the brick wall