I've been using HTC devices since... Ooh, one of the Orange SPVs (can't remember which) about 5 years ago.
The Vario 3 was by far the worst personal device I've ever inflicted upon myself. The UI was tediously slow (let's not get started on the driver swindle), the keyboard often didn't register presses, the alarm clock was still unreliable at best, and the facia started peeling away.
After using it, I swore to myself I'd never use another HTC device again. Ideally I'd like an iPhone but can't afford it, and I've got special discount on my T-Mobile line rental courtesy of a store manager of theirs I know. I could upgrade to the Vario 4, but is it as bloody atrocious as the Kaiser?