I think it is possible to do a mix. For example, there are several file-managers that are not heavy, I expect Thunar to work well on older machines, pcmanfm as

I think it is possible to do a mix. For example, there are several file-managers that are not heavy, I expect Thunar to work well on older machines, pcmanfm as well. For Office one could use something smaller like Abiword, though I never tested whether the performance of Libre Office is worse than Microsoft Office. My experience with such older machines is really that when using a good software selection, it was a lot faster and more comfortable than Windows XP. However, you might be right about video. I have an Thinkpad R50 here and I was indeed not able to get gpu support for video playback from its Radeon 7500, with the cpu being too weak to handle even SD-videos. I was not aware that was a general problem XP solves better (this specific machine I never used with Windows) :/