An open fire is essentially a large hole in your nice centrally heated house. Is that really what you want? I don't even find them pleasant to sit in front of, because of the drafts they create as the air is sucked through the house and chucked out of the chimney.
We have an open fire and a woodburning stove, and the open fire is for the chop a.s.a.p.
Having lived in houses which have at times been heated by wood alone, I can tell you that woodburners can actually heat a room to modern standards - a fire can make a room not actually freezing cold in patches.
There's no comparison - it has to be a woodburner!
BUT, before you buy one, you need to consider whether you have enough room to store the wood. They go through a lot of wood, and if you're going for a cleanburn stove, you should really be burning properly aged wood - which means that either you make sure you only buy dried seasoned wood (and send it back if it isn't), or you get your wood a year in advance and store it for a year to season it, which is cheaper / totally free but you then are effectively storing two years worth of wood in your garden at once.
You should also check how much heat output you need.
We currently have a Euroheat Stanford 80. We're thinking of buying something a bit different for the new stove, though, just because of the shape of the fireplace.