Thanks guys, based on the replies been doing a bit more researching and the Dakota 20 looks like definite maybe. Not quite as bulky as the the Oregon but bigger screen than the Etrex. Only concern is that I've seen a number of posts that mention the display can be hard to read, does anyone have any realtime experience of the Dakota when attached to a bike and could comment on this issue ?
Just for clarification I intend to keep my Edge 200 for data logging etc so the odometer issue is a non-issue, the extra unit will be for navigtion only.
Thanks