What would consider entry level? I use a Mac mini from 2012 (i7 with 8GB) every day and I'm not seeing any beach balls unless Flash crashes some web page.
"The net" is a very varied place these days. It would be helpful to mention how many tabs you're using, the sites you're visiting, etc.
My work computer is a 3GHz i7 Mac Mini bought in early 2015, with 16GB ram, and I still have times when news sites freeze and won't scroll because someone has done something stupid when coding the site.
But my system uptime is 89 days and I get to the point where chrome shows a red bar because it hasn't been updated recently. There are a lot of irritating little bugs, but the only things that seem unstable are individual tabs and MyEclipse.