Personally I like revives quite a bit. They are preaty awsome if you play them right. However I don't think I'd ever max them, basically you need to know about howmany you can support over two minutes.
I'd be more specfic but I lost some of my game notes with a Laptop crash earlier this week. But if you goto Arreats Summit and look under game basics they give a formula for your mana regeneration rate and you can then figure roughly how many you can keep going. Basically figure out how long it takes your character to regen 45 mana then divide that by 120 and you got a working revive number.
For example if you have a regenrate of 2 mana per second you'd have to wait 23 seconds between casts, thus you could support 5 revives with a regenrate like that. OF course this doesn't include casting other spells etc but you get the idea.
Then you try to stagger the casting of revive to that number to keep you army going and with 23 seconds between you have plenty of time to cast other spells as well.