My XP has always wanted it 50/50, so for the first 5 years, we alternated daily, with alternating weekends. Without going into the nitty gritty, I don't advise this. We now have a 2/2/5/5 situation, so they're here Mon/Tues, there Weds/Thurs, and we alternate the weekends from Fri after school to Mon morning. This is probably quite a good arrangement for those who can manage it. Unfortunately my XP is still a child at 40, so it's still very hard work for DH, me and the kids, but that's what you end up doing - moving mountains so that the kids can see their dad.
I would - get together a plan, in writing, of your suggestions for how contact could work, outlining the reasons. Think about how the kids' lives run, their club days, how uniform/lunches/pe kits work, and their contact with other family members if there are some.
Then when you meet, or email, as we have to, the emotional sting is taken out of the picture, you can be logical, and he cannot argue with the reasoning. Your argument will be putting the children's interests and routine first and foremost, and he would have to be pretty thick to go against it. As MOS says, you have to bear in mind things like clubs and child care. Both of you should be liable for childcare you have to arrange around your work/social lives. You can't juggle the kids for conveniences' sake, it's not fair on them.
In our situation, I'm lucky enough to have arranged my work to coincide with the days they're not here, but if I suddenly have to reschedule, then I get a family member or a babysitter.
I hope this doesn't all come across as being harsh and is at least a little helpful!