The Dell x51v's have their own problems, which include a limited Bluetooth stack (they make use of the MS one, instead of the superior Broadcomm used in the x50 series), and the occasional odd implementation bug (see threads about vanishing SD/CF cards). For the most part, they're good machines - especially the higher-end x51v which has the VGA screen that the previous poster here mentioned, and which can cost about $50 more than the hx2490... which itself is about the same price as the equivalent mid-level (non-VGA) x51 at the same clock speed.
Just keep that in mind when you make your decision: if you need the Broadcomm stack's functions (which include dialing from the contacts list), you might want to eye the HP instead of the Dell at the moment, until Dell puts out a new ROM image which has fixed some of the other issues reported with the x51 (including the crippled BT stack). Dell Warranty service isn't what it used to be, either, if one reads the complaints threads on AximSite.
For example, Dell's been saying they'd be fixing WM5 issues and releasing updated images 'next week' for about 7 months now... which is on par with HP's tech support these days.
Personally, I tend to rely more on SD cards for external program storage, so the internal storage isn't as useful as it once was - if they'd said the upgraded hx2000's had 128MB of program RAM, then that'd be really special.
New hx2000 series
Linear Mode
