Nice looking unit, but, I would wait until you can touch one or buy from someone with a solid return policy. Since it is new, there seem to be some discrepancies (Garmin does this too so I am NOT bashing Lowrance).
First off, the data sheet does NOT mention that it is waterproof or even corrosion resistant. Looking at the Users Manual, there are open slots for power, headphones, SD memory card, etc. so it does NOT appear to be waterproof. However, under their mounting section it discusses using in a boat and on a motorcycle.
The next "problem" MAY be that the map is not updateable. Again, we have differing info. The User Manual states:
A hard drive contains highly detailed road and highway mapping data for Hawaii, the 48 contiguous United States and most of Canada. You can’t change or erase the map. Another partition of the hard drive is available for you to store MP3 music files. The iWAY's memory also records GPS data you create, such as address book contacts.
which would indicate you can't update the maps, yet the data sheet states:
Maps can be updated through the internal USB port with a PC
and the User Manual goes on to say that the MP3 and picture files are stored on the SD memory card NOT the hard drive.
Me thinks someone did some "cut and pasting" from the i500C data sheet!
In either case, I have heard differing opinions on if you can plan a trip using a mapping software or the Internet and then upload to the gps OR download a previous trip for archiving. This is why many have written the i500C off as "worthless" and a feature that Garmin seems to excel in.
Anyway, just be careful where you order from (if you do) UNTIL either more is known or you can see one in person.