Coming from a System V and variants back ground and long time user of BSD and Linux for personal use, I've just moved over to a MacBook Air for work and travel and swish iMac for the home and I love it. I don't miss patching and recompiling kernels just get a USB device to work at all.
I feel right at home with it and it is easy to use and I can get right in there elbow deep with a terminal and shell commands and have been surprised at the array of standard unix tools in there.
Slick GUI, up there with KDE and Gnome.
As far as MDB files in MacOSX, try connecting to them using ODBC or JDBC. Open Office or Lbre Office (Base) is really good at this, heaps of tutorials on the net and I've had success following them, beats loading DarWine and Access in to MacOS X. Better still, find a parser that will read your Access file and generate a SQL file for loading into SQLite (standard in Mac) or MySQL, Oracle etc.
GoPro HD editing on the iMac and iPad 3 (Apple camera connection kit and SD card no greater then 32GB << very important with the Hero 3) is a dream with iMovie so simple to use and powerful, I was surprised especially on the iPad.
If only I could get my old UWATEC Sol dive logs of my wife's laptop into a Mac App then go native from there I would be stoked. Very happy that I download my Shearwater data.
I stuck one the big apple stickers on my KISS head and my O2 cells are now more stable and respond better. I stuck another one on my 4wd and it now crashes less, even with windows open.