Greg:
Don't be concerned that MapSource beta 6.06 has been withdrawn. That is common practice in the software industry - not just at Garmin. The engineers will float a beta for public evaluation by the 'keeners and enthusiasts' - then after collecting sufficient response (opinions, comments, bug reports, requests for additional functionality), the engineers will withdraw the beta, work on it some more, then either release the final product (which will have a higher number, usually ending with only 1 digit to the right of the decimal), or if they think further evaluation is needed, they will release another beta (typically identified by three groups of numbers, e.g. 6.0.6).
My guess is that the next release of MapSource will be a golden (final) release, but that's just a guess. In the meantime, for automotive use, 5.4 does everything we moto riders need it to do.
As for the SP 26xx, 3.50 is a maintenance release (meaning, bug fixes only, no new features). In theory, if you have not encountered problems with 3.40, then the upgrade to 3.50 will be transparent to you. But, the major bug that was fixed in 3.50 related to units with the European basemap (this bug was reported by the motorcycle users, by the way), so if you have a European unit, you really should upgrade to 3.50.
PanEuropean
