DSs are with their dad this weekend, so hopefully the revision is still happening.
DS3 is maintaining his 2 hours a day plus Tassomai for 1/2 hour, outside school. If he has an after school revision session with a teacher, he's counting that as one 1/2 hour session. Seems to be only Chinese and History that he's doing those for, his 2 weakest subjects, I think, (or for Chinese, the most strict teacher!)
He doesn't seem particularly mentally tired but as some PPs DC he's not exactly been over-exerting himself. 
He's still only doing the 2 hours on a weekend, but at least that makes it feel like the weekends are time off.
I got another grade card this week. That's 4 this year. I'm not sure why we are getting them so often.
He has improved or stayed the same in all subjects, so that's good. Not sure how they are judging it, maybe on past papers? If he gets what he's now predicted I'll be very happy. 9 for maths and 8s for his other two A level choices and mostly 7s with a few 6s (or Bs) otherwise. I guess we'll see in August!
I'm sort of looking forward to him starting now, slightly envious of your DC doing IGCSEs who have some exams completed. It will be nice to cross them off.