1. For the Dell, it depends on the amount of table space you have. Personally, I would go for the U3011 but since my table is small I had to get the U2711.
2. Get the Mac Mini with Fusion Drive and 8GB RAM. It's easier to upgrade RAM than the hard drive in the future. Also, you are getting better noticeable performance because you're upgrading the slowest part in the computer.
1. For the Dell, it depends on the amount of table space you have. Personally, I would go for the U3011 but since my table is small I had to get the U2711.
2. Get the Mac Mini with Fusion Drive and 8GB RAM. It's easier to upgrade RAM than the hard drive in the future. Also, you are getting better noticeable performance because you're upgrading the slowest part in the computer.