I agree about being cautious about investing in a dedicated unit; mapping is constantly changing and your nav is only as good as your maps or charts. Again, find maps that suit your needs and THEN find the hardware to use them. Not all apps use the same content, and with the Garmin, Lowrance, Magellan dedicated units you are likely to be stuck using their proprietary maps, which may or may not suit you.
For example, I dumped MotionX when it lost Google. I have come to love their aerial photos, although Bing/MS has caught up. Using street view is amazing. Yeah, you can do without it, but why pay more for something and NOT have it? Some of my toughest navigation was in cities, or finding the turnoff, NOT on the backroads where things haven't changed in 50 years.
And there are SO many useful navigation apps besides just the GPS/map apps. Logging for photos. Logging for training. Sharing, including trip updates for safety. Surveying apps, like Theodolite or Sun Seeker, both of which use augmented reality (you see sun paths overlaid over realtime viewfinder video, useful for photography and camping in shade). Peakfinder, for IDing the mountains on the skyline. Various compasses, which make it easy to shoot bearings (and Theodolite or Spyglass). Clinometers; set your wheel's camber. Calculators and almanacs (maybe you use a sextant and wanna calculate your position from that). Range finders. Lap counters and timers, with video, for the track or just speeding. I am sure there are more. And I can buy most all of this for probably less than the degrees-minutes-second calculator and almanac I had to buy for celestial nav. It's amazing.
If you don't wanna commit to an iPad (and although I own one, I gotta say that Android may have it over Apple on this because of the ability to attach external GPS receivers at a higher refresh rate), just find the cheapest smartphone that maybe will work even without a data plan. It's still gonna be cheaper than a Garmin with maps. I still use an iPhone 3GS with cellular and find it useful as a data logger.
And there's also just a plain old GPS without maps, although those are getting harder to find. Just a LCD screen, waypoints, and some way to get them in. USGlobalSat still makes a couple. Use it with a Landmark Atlas or other paper map. Still works fine if you have basic routefinding skills, and if not, good way to learn. It will hold you over till you can afford a pair of Google Glasses.....:Wow1:
