I suspect those of you who see RE as wholly positive are blinkered, very likely through lack of experience of anything other than one particular education system. Lots of people (I include myself) have been damaged by religion at school.
By contrast, my own children (we were not in UK) went to 'Ethics' classes at school, independently of their normal everyday curriculum, taught by a different teacher from Primary on, while their friends went, variously, to Catholic, Protestant, Jewish, Islamic religion lessons - at parents' choice.
Giving time in this extra-curricular way set religious education where it belongs, imo - apart from the school curriculum as such. They (my own children, that is) ended up as well-balanced, moral individuals with what I think of as an appropriate attitude to religion - they're wholly bemused by the background ideology, but appreciate that other people think various religions make sense and accept that. Their own children aren't at school yet, and I wonder what those of them in UK will do. Take them out of RE? I'll try not to tell them what I'd do, but they'll probably know. Their choice, though.
Those of my children who have made their home in (ahem!) more enlightened countries won't have to make this choice for their children when they begin school.
Making RE into comparative religion or whatever misses the point imo, which is that children ought not (and, as my experience shows, quite clearly need not) be taught religion at school - keeping RE as a compulsory school subject gives religion itself a wholly spurious respectability that it no longer warrants (if it ever did).
So, OP, my advice is to bite the bullet and remove your children from RE as is your right. The more people do this, the better off we'll all be. And you'll be doing your DCs a favour.