A question for all of you current (and former) 305 owners.

I'm looking for a higher tech / more reliable method of following the cue sheets for the weekend rides that I do. This is especially important since one of the local towns has declared war on "arrows" and many of the rides will be conducted without the benefit of complete road markings.

Most of these rides have GPX files available (from MapMyRide, Gmap-pedometer, Bikely, etc) for download. I presume that these can be loaded in the GPS as a "course".

I know that the 305 lacks the mapping features of the 605/705, including "turn by turn navigation". However, if I have downloaded the course, will it give me audible and visual cues of the upcoming turns?

I know that the 705 will do everything I need, but if the 305 will do it for less money, I'd rather not spend the money. . It's likely that the 705 would be better for getting back on course after you make a wrong turn, but it's hard to justify for that feature alone.

Anyone have direct experience to share?