My parents had a system like this, all our heating and hot water ran off the "range" - aga-like thing which took wood/coal and anthracite.
It is a lot of work, and ime only works if one of you is at home full-time.
My parents ultimately converted back to gas, once my mum had gone back to work full-time.
I remember the misery of waiting a couple of hours for things to warm up (no hot water either) when I got home from school.
I am also rubbish at lighting fires so it was a lot of effort (a friend has recently put one in in her house and finds lighting the fire and cleaning it out a real chore).
And then there are all the trips out in the cold to get fuel, and the time spent stacking the logs which are dumped in your garden after delivery...
DH suggested putting something similar in our house, and I was totally anti because we both work fulltime outside the home and have enough on our plates with 2 young DS too.
He also looked at the pellets, but as mentioned upthread, there are several disadvantages.
We have an oil-based heating system which we don't like (environmentally speaking) but on the other hand, we calculated that it would be madness financially to replace our existing system which works with a new one - we would never get the money back.
We are waiting til our current system breaks down and then hopefully things will have moved on with the wood pellets thing - but they are hideously expensive at the moment.