Hi I just bought this one:

http://cgi.ebay.com.au/NEW-Cateye-St...item2303a315df

for my new bike - LOL purely for the look of it! (weak, I know!)

I wanted to do away with the cable on the bike.

The unit itself (Cateye Strada RD300W) is working great on the one ride I have had and affixes to the stem nicely.

Yes, heavier unit than with wired and you have the battery issue. One less cable is cool though!