No... I'm using the phrase "image stability" the way IT managers use it.

Google for it. It's the hardware and software consistency throughout the product line. IBM for example, promotes image stability with their commercial line of desktops and notebooks. They'll guarantee no change in the hardware and software image so that companies can standardize. If there's a new chipset stepping, they'll keep using the old one in case there are incompatibilities. They won't change to another vendor for the NIC. Et cetera et cetera.
What I'm trying to say is that Dell doesn't yet have a track record for their line of PDAs. The latest X3 has an entirely different set of accessories and sync connector compared to the X5 (lack of image stability). As an IT manager, if I had invested in the X5, all the accessories would have been incompatible. If I had bought for instance, the iPaq, my investment would be preserved since all the accessories including keyboards, expansion packs, batteries, et cetera are compatible with the h3600 up to the h5500 series. All this makes it unlikely that many companies would have invested in the Axim.