ok, but are there any downsides in terms of SEO if I leave URLs like this?
That's because I am using good CMS, and I can make categories and put articles inside those categories. What I'm saying is that I can make good usability on my site without changing my URLs.
Basically, I have main menu on the top:
Home ¦ Category1 ¦ Category2 ¦ Category3 ¦ Category4
Then if you select Category1, it will take you to example.com/main-article-from-category1
and on the left side, there will appear block with links to articles that belong to Category1. So whichever category you choose, block on the left side will display links to all articles from that category.
So I think this will make good user experience. I might add breadcrumb trails into the mix.
What do you think? and should I really change URL structure? btw I am using mod_rewrite for URLs, there are no real physical directories.