OK..so what about your Ubuntu machine makes you want to switch to a Mac? I mean, if things are working OK with your Ubuntu machine (being a former Ubuntu Linux user) right now..why consider the switch?
The barrier of entry into Mac's price-wise is significantly higher than a computer that is capable of running Ubuntu REALLY well..
Regards
I can see your point with the iPad and iPhone. Very simple to use with OSX and a Mac. And since the core of OSX is Unix anyway, you would feel like you are in a totally strange land. Terminal and everything in OSX.