P1fel sums the two a/c up well.
I too began on Heralds in the mid-70's and because it was my first airliner, I at first I thought it wonderful! It handled well but the performance was dire - (eg)we would use standing waves off hills to gain altitude because it was the only way we'd make our cleared level to cross (say) an airway. It was well-built and was very stable in strong X-winds & bad wx.
Then, after 500hr or so, I went onto the F27 and realised why the world was full of Fokkers! Faster, better performance, does what the sales brochure says. But, as others have stated above, not as nice to handle, all over the place in strong winds and a pig to land well. And we all looked on enviously at Avro748 drivers, 'cos we all knew instinctively it was the best twin-turboprop of the day.
Funnily enough, I went on to fly the BAC111 as my first jet. Then I went on to fly DC9's and very quickly realised why the world was full of DC9's and not BAC111's - a DC9 on one engine had a better performance than a 111 on two! Not unlike comparing the Herald and F27, except that the '9 was built like the proverbial outhouse, had fighter-like performance due to those big JT8's, was pure joy to handle, and the mount of choice in appalling weather.