I have an IBM Workpad C3 (the Palm Vx in black, essentially) I can hardly live without it.
I like the slim form factor PDA the best. I had a Palm Pro way back when and it just stayed in my briefcase. One that can fit in a shirt pocket is seriously mobile.
Those Visors that are slim AND have the Springboard capability -- wow. When it moves to colour, I will be due for an upgrade.