Another clear reason to not use viva street. 
Decent punts can be had from VS, but with a few provisos, you have to be prepared to walk if not as advertised, either girl or services. This means that you can't be desparate to empty yer sack, because if you are you likely won't walk when you should. Because of these I personally would not travel far for a VS punt and a reasonable chance of having to walk, again a long journey makes you more likely to stay when you should walk.
If you are the sortof person who is too embarrassed to walk, probably better not to chance it.
