Nick,
I am the proud owner of a Suunto Core, and the former owner of a Suunto Vector. I have never owned the HighGear Axis, but did a little comparison shopping at one point. I cussed the Vector every day I had it for being inaccurate, imprecise, non-durable, etc. By contrast, I would HIGHLY RECOMMEND the Suunto Core. I am absolutely thrilled with the precision, intuitive use, durability, aesthetics, etc.
Here is my review of the Suunto Core on REI.com (I have the Light Green version):
The Suunto Core does not disappoint – it performs exactly as Suunto claims. Far and away the best altimeter/barometer watch on the market.
I am most impressed by the Automatic Altimeter/Barometer Mode. This feature solves the biggest problem with previous generation alti/baro watches (including the Suunto Vector and similar) by sensing whether changes in absolute pressure should be attributed to elevation change or weather.
Suunto says that the Core accomplishes the automatic alti/baro switch by sensing movement, or lack thereof. What it actually seems to be doing is sensing the rate of change in absolute pressure. If the observed pressure changes faster than could be attributable to ordinary weather, it apparently judges that you are moving and enters altimeter mode. The programmed threshold has worked flawlessly for me thus far. Plus, you can easily override this feature and force the watch into altimeter or barometer mode exclusively.
The digital compass performs as well as any I have seen. I am not a particularly big fan of digital compasses in general, so I always carry a traditional sighting compass as my primary navigation tool, but the Core provides a handy backup.
The alarm and other audible indicators on the Core seem to be louder than previous generation Suunto products, and the audible indicators can be turned off.
The crystal face is also improved over previous generations, and seems highly scratch resistant.
Overall, it seems that Suunto has addressed every critism of previous generation altimeter/barometer watches, and provided a very elegant solution. This watch has very quickly become one of my most trusted gear items. The Core is a worthwhile upgrade to your older altimeter watches – the improvements are that notable.