Having own several pair of boots, i know how uncomfortable it can be when walking in boots for too long or too far. Weight is one of the issues. Would you want to drag a pair of heavy boots around? Not me, at least! Another issue would be the material. You wouldn't want to wear a pair which leather is so stiff that it felt like you are wearing wooden clogs. Last but not least, the soles are very important as well, it should be at least lightly padded. I don't think anyone would want to feel that they are walking on concrete.
I think i have found some good ones at Dr Martens. Docs or DMs, whatever you call it, are known for their air-cushioned soles. They are not particularly light but surely not heavy. As for the leather, it's not too stiff and it will easily soften as you wear it...
Let me introduce Ormond (left) and Jeffery (right). The most main reason why i chose them is because they are unlike the others which has a thick and bulky tip on the front. For me, i like my boots too be slim and sleek. I don't really like the classic ones like the 8 hole 1460. Ormond is nice with the wingtip brogue design while Jeffery has the slim and sleek aesthetic with some minimal stitching on the sides.