I can't say I'd give it much of a leg up over the x51v. Remember it's the same OS. Microsoft sets the playing field pretty level here.
The x51v has a much better screen and the battery time is leveled by opting for the next size up battery. Wifi performance and range is usually panned on PDAs (my Toshiba e80x is abysmal) but the Dell and HP units have been very usable overall.