The advantage of note taking software like One Note and Evernote is that it is extremely easy to clip bits of webpages which might be of interest and requires little more effort that one or two mouse clicks. A second advantage, particularly with Evernote, is that your data is stored online and you can sync it to your laptop, desktop or tablet. (it's possible that this also applies to One Note 2010 and later).
Note taking allows you to separate the searching and gathering of data from the collating and entering of data.
The disadvantage is that you can gather too much. It is necessary to discipline yourself to regularly review the data you have gathered and do the work of entering it into Legacy and I would recommend removing the remnants from your notes.