But besides habitat, there is another crucial difference between the different sites - productivity. Never mind the quality, feel the quantity.
Take for example the case of Leam Valley vs Napton (reservoir and hill).
A typical walk through Leam Valley, such as the lunchtime one I took earlier this week, can often turn up very little for much of its duration. Sure there will be from common birds some song and movement around the trees and hedgerows; an occasional moorhen disturbed from its bankside shelter; and perhaps a buzzard calling high overhead.
But often there will be next to nothing, and the real hope all the way out will be that the scrape will deliver. And often it does - but with more meagrely measured offerings than some other sites (as we shall see in a moment).
This week's visit was one such occasion, with those meagre but no less rewarding highlights on and around the scrape including: great and repeated views of a kingfisher fishing in front of the hide; a small flock of brightly-coloured chaffinches and goldfinches; and - star bird of the day - three shovelers, a male and two females (initially overlooked as mallards by a stupid and over-eager eye).
Compare and contrast with Napton on Saturday morning. It was my first full session at Napton for many a long while, and it was fantastic in every respect. Great weather, high spirits and a monumental bird count.
Where to start? On the reservoir itself there were fairly typical numbers of coot (80+), tufted ducks (25), mallards (18) and gulls - 70-odd black-headed and about 20 common. Snipe seemed to flush from every bank and reedbed, I counted more than a dozen flights in all. New on the water were 9 wigeon; 4 lapwing flew south; three fieldfare flew past; and decent numbers of starlings arrived in two biggish groups - 50 then 100+.
Away from the water I was teased for a while with distinctive 'seep, seep' calls; eventually I was able to track them down and identify a little flock of meadow pipit, a welcome bird which I don't see often enough. Plenty of skylarks passed in good voice overhead, a mistle thrush did likewise, a few pied wagtails moved around the reservoir edge, and a male sparrowhawk made a spectacular, but unsuccessful, low pass over a field of starlings.
By contrast the hill was quiet, but I still managed to add jay, great spotted and green woodpeckers plus another mistle thrush to the morning's tally.
So there you have it. Both rather wonderful trips, but in such different ways - one a detailed and close study of a handful of birds, the other an overwhelming spectacle of everything that autumn birding has to offer.
And by way of a final comparison, it was on to Brandon. So what does a specialist nature reserve managed to perfection for more than 20 years have to offer? Well, a bumper crop of wildfowl for one; plus (and saving the best 'til last here), a pair of stonechat from the new Ted Jury Hide.
Oh, and a tearoom serving a full English breakfast. The perfect end to a morning of 46 bird species - a happy marriage of quantity and quality in equal measure.
Bird of the week: Stonechat (Saxicola torquata) - I could honestly have picked any number of birds this week, but this little gem has edged it. Normally a bird of western and southern heathland and coast, they disperse more widely in the winter, so a real possibility wherever you are. More on them in the next post.