i've worked on integrating and managing mac clients in the enterprise for over 10 years, and it doesn't have to suck.
first off, apple
can be a difficult vendor to get support from. they're getting better, especially lately, but they definitely have had legit issues in this area. my current employer has an alliance level support contract, and i've been happy for the most part.
second, they make a decent active directory client (caveat- i'm only talking about 10.7.2 and .3 here. the apple AD plugin was straight up broken for many environments in 10.7 and .1) so account management is done for you already in most shops. osx boxes have their faults as AD clients still, even in 10.7.3, but i've seen more commitment from apple to fix the issues in the last year than i ever have before- 10.7.4 is evidence of this.
third, client configuration management through MCX is very nice on OS X. I like it better than group policy. many third party application settings can be managed using the same tools, too- office 2011, for instance.
fourth, MCX is morphing into mobileconfig profiles . . . .the very same mobileconfig profiles used to manage iOS devices in the enterprise. profile support was introduced as an addition to traditional MCX with lion and will be greatly expanded in mountain lion. this is a VERY good thing- OS X deployments will be easier to piggyback off of iOS infrastructure instead of requiring mac-specific servers and admins. plus you can still use your custom MCX commands in the new profiles, so its an easy transition.
fifth, JAMF and the casper suite. very, very nice imaging, inventory, remote control, MCX/profile delivery, software distribution, patch management, and self-service system for OS X and iOS that makes sccm look . . . unwieldy. the server runs on any platform that supports java, tomcat, and mysql. i run mine in a windows 2008r2 vm.
sixth, if you don't want to pay for a solution like casper or absolute manage, you can roll your own client management system using deploystudio, munki, puppet, etc . . . these are all examples of a small but active open source community creating osx enterprise tools that are very high quality. google has released many tools, cauliflower vest most recently, greg neagle/disney have improved on the apple SUS with reposado . . . there's a lot going on, and it's all great stuff. even adobe has good+free repackaging and deployment tools these days.