Hi Mary K,
I have a gas patio heater and the only problem I find with it is that when there is only about 1/4 left in the tank there is not enough pressure to keep the patio heater going. I also have a gas BBQ so I use the 1/4 left in the tank for the BBQ - works fine - the problem is is that I have about 3/4 1/4 tanks in the garden now (use the heater for alot longer than the BBQ).
Apart from this little problem the gas ones are very good.