I have been using my IBM T42 laptop for 6years. Over the years, it has gotten slower. Sometimes, it is unusable. Internet Explorer is usable, but sometimes it can be slow.
How many years of usage can I expect from a desktop like the HP Pavilion Elite HPE-450T? I will use the desktop for surfing the internet, writing word documents and printing. How many years of usage can I expect from the Gateway SX2850-33 desktop? I will be using the Gateway for surfing the internet, writing word documents and printing.
If you surf, word process, and print . . . honestly, all you need is the i3 system.
You can keep it running fast by not installing a lot of junk downloaded from the internet like toolbars, etc. Each one of them slows you down. Also make sure your hard drive isn't near full, and defragment it occasionally. Also delete unnecessary temporary files (system maintenance).
All that Two boxer said.
Plus, ditch IE. Try Chrome or Firefox (or maybe Opera?), and I guarantee it'll speed up your experience by a bunch.
Besides that, yeah, you should be fine with that. If you really want to save money, even today's Pentiums can handle the web...