Just calculated my gearing...

Actually there is an increasing body of research which supports the view that rather then force a high cadance you should find your natural pedalling speed and gear up to the point you feel comfortable.
I toodle along at 85 ish revs per minute no matter what gear I use so I have settled on 48:16 as comfortable to me.
I think it really is down to what you are happy with.

Toodle pip
Higher cadence is better for long rides, it's a well known fact. You're using more of your muscles, moderate stress on quad and moderate stress on calf rather than high stress on calf and low stress on quad. Whilst this is slightly less efficient in terms of calories burnt to power output, you will find that it is beneficial because there is lactic acid buildup because you are not overstressing either set of muscles.

That said, 85 RPM is a very good cadence. Anywhere between 80 and 100 is in the right range. 85 RPM x 70 gear inches is MUCH better than 70 RPM x 85 gear inches. By all means go for higher gear inches if you can keep your cadence in the right range.