What are the upsides downsides to a LPG Autogas conversion.?

[http://www.asminor.info/ljacoby_2000/rumpe/ginorumpe.jpg]
(http://www.asminor.info/ljacoby_2000/gh07.html)
With “auto gas” being roughly 60% of the cost of petrol, investigating a conversation is attractive but not if it is just simply an exchange of costs and the whole deal just is a contra entry.
Much lower “mpg”, increased service costs, insurance, more “wear and tear” are just some of my thoughts. Also how does auto gas effect performance ?
Hence what are your experiences (in the UK please), costs, regrets and pleasures concerning the topic.

[our team groundhog 2007]
(http://www.asminor.info/ljacoby_2000/gh07.html)

i personally use lpg and it is both cheap and enviroment friendly. and there are no extra service costs with it