Ash has much lower BTU and burn time for a given output rate, but that's fine, I'm working from home these days. Oak does present more problems with coaling than most other woods, as stoveliker already indicated. Not a huge problem if you don't need maximum BTU's all the time, but a definite point of frustration for those who do.
I care less and less about what I'm burning, as time goes on, give how I have been running the stove the last few years. I load it 2x per day, and set the knob to a point that gives me roughly 12 hours burn time. If that's too much, I have a second mark on the knob for 24 hours, and can roughly eyeball 18 hours in-between. Any heat required, beyond what the stove puts out, is handled by my six zones of oil-fired hydronic (four floors, six zones), three heat pumps (more remote zones), or resistive baseboards (third floor above stove). I don't bother trying to manage the house temperature with the stove anymore, doing that was frankly too much work for a house this big, I just try to avoid over-shooting in warmer weather.