So, is Lion better than Windows 7? Should a Win7 user even consider moving to the MAC OS?
That's a silly question to ask. PC hardware doesn't run Mac OSX (no, you shouldn't set up a Hackintosh). So the question is now "Is it worth my while to buy a Mac?"--and the answer to that, like the answer to the OS question, is "It depends on what you do with your computer, what you want to do with your computer, what you find good about your current operating system, and what you find less good about your current operating system."
Personally I have a 13" Macbook Air as my laptop. It's the fifth Mac laptop I've owned in my life. I like how lightweight, slim, and easy to carry it is, the excellent construction quality (especially the touchpad and keyboard). I think it's good value for money in terms of the stuff inside the box. I like Apple's technical support, and I live near an Apple store so it's easy for me to get in-person service. I like the Magsafe power connector. The battery life is decent. I love that it has an SSD. At this point, the MBA is the only high-end laptop I'd recommend to anyone for anything. For lower end laptops, I'm not sure what I'd recommend--in many cases I'd recommend a tablet. But for people looking to spend $900+, say, on a laptop, I'd recommend the MBA. So to me, the OS question is already secondary to the hardware question. Also, I like that Apple ditches legacy technologies. I don't like hard drives. I don't like disc drives. I don't like printers. I don't like ethernet. I love the resale value Mac products have, as well, so I know that when I upgrade I'll get a pretty significant downpayment from selling my current hardware.
But I like OSX a lot. I love the default software stack. iPhoto is great. iTunes runs well on OSX, although I have a number of reservations about it. I think Transmit is the best FTP client every made. I love the default development stack and being able to code in a variety of languages without having to worry about setting up development environments. I like the Terminal, and I have a lot of experience with poking around the innards of the system. I like how software updates are handled, I like the Mac App Store. I like a lot of third-party software. I love the built-in support for PDFs. I love the built-in print-to-PDF. I love QuickPreview. I love the shareware development environment where small independent developers make beautiful, excellent, robust applications--some of the best applications designed in years are on OSX (I'm thinking of stuff like Sparrow, for instance, or 1Password, which is Mac-first) I love that Apple's OS updates have cost $19-29 for the last several years rather than the way more expensive default Windows prices. I like that defragmentation is not needed. I personally prefer Mac Office to Windows Office. I like the memory usage model. I use Bruji's DVDPedia and Gamepedia to track my collections. I like the outright crashes are exceedingly rare. I like the way gestures combine the hardware's strength with great OS support. I like that Malware is not a going concern for me. I like the Dock. I like the care put into the look and feel of the operating system. I like LaunchPad. I like Expose. I love the way text renders on the screen. Many of these things have equivalents in Windows--and I like Windows. I use Windows on several of my computers.
I don't like the gaming support. I don't really like Finder (the Windows Explorer equivalent). I don't like the "smart-maximize" button, which has always struck me as dumb. I don't think full-screen apps are well implemented. I don't personally use Safari. I don't like how ridiculously high a lot of shareware applications are, and how freeware is less common on OSX. There are some ways in which the Windows taskbar is more efficient than Dock+Expose. I don't like skeumorphic design in some applications. I don't think iCloud is well implemented.
I'm writing this from a W7 Desktop. I wouldn't recommend a Mac desktop because I don't think they offer good value for money.
I have been a sysadmin and/or programmer for 10 years. I have XP, W7, W8, and OSX installs on my personal devices. I have a Kindle, an iPad, a Nexus 7. I have an iPhone 5 and a WP7 phone. I've administered Windows, OSX, Linux (several distributions, both physical hardware and remote servers), SCO UNIX, and AIX servers. There's no silver bullet. Different things are good at different things. If you had asked me if OSX 10.3 and 10.4 were better than XP, I'd give you an unambiguous yes. But W7 is a very mature operating system and a pleasure to use, and I'd gladly use either W7 or OSX10.8
OSX is a great operating system, and Apple makes great products. I can't see anyone finding either to be a disaster. But whether you want to switch is a bigger question than "Which is better?"