I like Macs a lot but what is really important for me is their build quality and the O.S. OsX is a fantastic operating system and I cannot see myself going back to Windows as I do other stuff besides audio (development). I currently have a 2011 13` MBP and a 2009 iMac.
If i was on the market for a new laptop, I would get a retina Macbook Pro 13'' or 15''. There are no match for them, even HP Elitebooks (i had one in a previous company).
But to replace the iMac I'm really thinking about building a hackintosh. With little money you can get a fantastic machine and very upgradeable.
Take a look on the suggestions here: tonymacx86 Blog: CustoMac