With my personal experience of being sort of a "computer/electronics geek", IE is the worst by far. I have used IE, Firefox, Safari, Chrome, and a few others and have stuck with Firefox. Chrome works really well for doing small things because it doesn't take up a lot of space with add-ons and such. I switched to mac early this year and absolutely LOVE it! Have had no problems, extremely easy to use, and very fast with everything. Over the years, I had way too many problems with PC and Windows that after spending thousands of dollars in repairs and new PC's and laptops, I went the other direction and haven't looked back. I truly believe in the saying "you get what you pay for".
You may want to try chrome with doing orders since it isn't a browser that will lag because it doesn't use a lot of space.