I've had alot of few different types of boots in my time. All of them are military style boots, so apologies if you're after a more civilian looking type of boot.
My first pair of boots were Magnum classics, I found them light and very agile, however they have very little ankle support, especially when carrying weight. The fact they weren't waterproof was a big problem.
Next I got a pair of pro boots, these again are military boots, actually on issue to soldiers now. At the time, they weren't and were alot more expensive. The offered excellent support, were very warm, fairly light, however I didn't like running in them, since they weren't exactly very flexible.
I think the next were LOWA (Lowa combat GTX) boots, extremely warm, beautifully comfortable, but very heavy. Excellent support and rigidity, but hardly any flexibility due to them being so thick. Also, because they were goretex, and if you're going anywhere near water, you should never buy goretex boots, they took an age to dry out when they were wet inside.
Now I've got a pair Altbergs (Altberg defender microlights), they're by far the best so far, extremely light, easy to run in (like trainers), just about enough support to do decent weight carrying, and yet still flexible enough to bend over, kneel down, and spring about. I would definitely recommend those from experience above any other boot I've tried. Also, they've needed next to no breaking in, and when the soles are worn down, I'll just send them back to the factory in Richmond, Yorks, and get them resoles. Magic
One downside to both Altbergs and Lowas, is that for some reason, the laces always snap on me. One lace snapped on my Lowas, and both have snapped on my altbergs (I've only had them 2 months), so definitely get yourself a spare set of laces.
However take into account that everybody's feet are different, and you can't beat trying them on in a shop and finding out for yourself what they're like. Hope you find what's best for you.
A really big downside to all these boots is that they are very expensive. However as any soldier will tell you; footwear is somewhere you can't afford to cut corners.
Hope that helps.
Spunyarn