Keep in mind, not everybody is running a desktop browser with that sort of cpu horsepower behind it.
Half of the iPhones ever sold - something like 80 million devices - are pre iPhone 4. There are a lot of low end Android devices on the market _right now_ with worse browser performance than an iPhone 3 (I've got a <6month old Huawei U8110 here as an example). Sure, top-end Android devices compare well against an iPhone4S (I'm pretty impressed with the Galaxy SII I've got here), but the bulk of Android devices in the wild are not late-model-top-end devices.
I had to drop an entire development branch from a project late last year due to insufficient performance of mobile device on-handset ajax. (We fell back to on-server html rendering and innerHTML updates, and even _that_ is annoyingly slow to me on low-end phones.)
And unless you have gathered data showing otherwise, this _probably_ really does apply to you. I was collecting some mobile use data last week - across ~70 websites that I've got Google Analytics access to, the average mobile visits was 14%, and the peak was just over 28%. This was across a range of markets and a variety of levels of "mobile friendliness" of the web design. (Biggest and probably most obvious takeaways from that exercise: B2B sites are a standard deviation or more below average for mobile visits, personal/leisure B2C sites up to one or two SD's above average. 80+% of mobile visits exit on a page with contact details - a phone# or address.)
Half of the iPhones ever sold - something like 80 million devices - are pre iPhone 4. There are a lot of low end Android devices on the market _right now_ with worse browser performance than an iPhone 3 (I've got a <6month old Huawei U8110 here as an example). Sure, top-end Android devices compare well against an iPhone4S (I'm pretty impressed with the Galaxy SII I've got here), but the bulk of Android devices in the wild are not late-model-top-end devices.
I had to drop an entire development branch from a project late last year due to insufficient performance of mobile device on-handset ajax. (We fell back to on-server html rendering and innerHTML updates, and even _that_ is annoyingly slow to me on low-end phones.)
And unless you have gathered data showing otherwise, this _probably_ really does apply to you. I was collecting some mobile use data last week - across ~70 websites that I've got Google Analytics access to, the average mobile visits was 14%, and the peak was just over 28%. This was across a range of markets and a variety of levels of "mobile friendliness" of the web design. (Biggest and probably most obvious takeaways from that exercise: B2B sites are a standard deviation or more below average for mobile visits, personal/leisure B2C sites up to one or two SD's above average. 80+% of mobile visits exit on a page with contact details - a phone# or address.)