In reply to Al Evans:
Problem with the Guide as an approach/climbing shoe is one, not so good on wet grass and two, not so good for walking in compared to an approach shoe with a more pronounced rocker. Guide Tennie is great for climbing in and pottering around at the bottom of the cliff.
As far as 5.10 goes I think, and I have owned both, the Prodigy is superior - I did Tower Ridge in a pair, car to car, have followed E2 on grit with them and led up to VS. You can also fit a crampon to them.