the obvious disadvantage is no high-dpi touchscreen so you're back to a Blackberry or Palm Treo, things that were sold as business phones.
There are dozens of UI effects which rely on the GPU, and there's just no such thing as a 2D GPU these days, it makes no sense unless you're building a retro console or something.
So don't do that exact effect? This is a pretty weak objection.
> there's just no such thing as a 2D GPU these days, it makes no sense
This might be stronger but I'm not an expert on pixel pushing.
It looks less nice and is limited in some ways, but for business needs to does the job perfectly.