In reply to MariaJGlez:
I just wanted to post my own experience, as you might find it helpful. I lead up to about HVS/E1 and am reasonably experienced. I have a few partners who are just starting out with their trad, and I love climbing with them. To me, it is about the person you are spending the time with, not just the grades you're climbing. If I like spending time with the person, the grade doesn't matter so much. I find it super rewarding to climb with people just starting out, as you feed off their joy and psych. When someone leads their first severe and they're pumped and you can congratulate them, to me that's way more significant than just following your mate up some VS. I also love teaching people new things and tricks and offering advice, so this is another plus.
The other great part about climbing with someone below your own level, is that you kind of get to have a little rest seconding them (not to belittle your ability at all...). I like climbing with people who climb harder than me as well, but it can sometimes be a real chore when I'm blown from seconding their sustained 5c/6a and then realise it's my lead next.
Another plus is that there's no danger of them saying "hey I was looking at getting on that absolute classic 3 star route you have your eye on today".
In fact, I'd say the worst people to climb with are people climbing a similar level to you, as they steal the routes you want to do! You're also much more likely to get what I call 'Second Syndrome', where you're put off leading a certain grade as you found their climb tricky on second. You don't get that so much seconding easier things, and you more expect to find hard things hard so are not as deterred seconding routes above your grade.
Post edited at 16:19