OK, after playing with the ViewSonic V37 Pocket PC and comparing it to my Dell Axm X5.

My first impressions of the V37 were largely positive. It is certainly thinner and lighter than the X5. The screen is just a smidgen larger, but you can only see the difference when placed directly next to one another. The brightness and contrast of the display was very good and virtually identical to the X5. It has a reasonable feel in the hand, however it does feel a little more delicate or flimsy. The Axim has rubber grips down the side that give it a solid, slip-free feel in the hand. If my hands are a little dry and slick, the V37 feels like it might be able to slip from my hand.

The only standard expansion slot is an SD slot in the middle of the top of the device. It does support SDIO which is just now an emerging standard for using an SD slot for things other than memory, much the same way that Compact Flash slots are now used for a myriad of non-memory devices. They included some collateral in the box that offered an 802.11b SDIO card. However when I went to their site it is still not available. What is taking so long to get the SDIO devices onto the market? Wireless SDIO cards were announced almost a year ago to be shipping Q1 of this year.

I transfered my 128 Meg SD card from the Axim to the V37 and it immediately recognized it and was able to read it just fine (I would hope so...). I have some programs on the SD card and so I ran them. They seemed to load faster on the V37 than they do on the X5. Probably because the SD slot is a newer design and uses the full 4-bit transfer, although I don't have any hard facts on this.

The V37 does't have a user-replaceable battery like the Axim so you are probably stuck with sending the device to a repair center for a battery replacement. However battery technology these days is getting better all the time so I imagine that the built-in battery will give several years of useful life. I also have not run any battery run-down tests so I can't give any details on the battery life.

The docking stand is fairly small and lightweight. This is both good and bad. The connector on the docking stand is fairly tight so you have to hold the base with one hand and undock the device with the other. It is also for this reason, the docking stand is more portable so you can more easily take it with you. The Axim docking stand is a beast. It is very heavy and allows one-handed un-docking. It also has a slot in the back to allow you to keep a second battery charging which contribute to the weight.

Since the V37 and the Axim both use a 400Mhz XScale, I can't say that one performs any faster than the other. They seem to be on par with each other.

Pros:

Thinner and lighter

Screen is slightly larger but is about the same brightness and contrast as the Axim

SD slot that supports SDIO

Seems to read from the SD card faster than the X5

Unique telescoping stylus

More portable docking stand

Cons:

Less substantial feel in the hand. More flimsy feeling.

SD only. Limited expandability due to slow industry adoption of SDIO expansion cards

No user-replacable battery

Less sylish. More boxey.

Headphone jack is on the side rather than the top (can't listen to audio with it still in the slip-cover case)

Requires two hands to undock the device