I will not speak to the actual apartment as that's all about what works for you and you should know that best.

In terms of location, 4th link (Odeon) is by far the best. Yes it is very touristy but it is that way for a reason which is the same reason you are there. It is a beautiful neighborhood and close to a lot of attractions, the river, Luxemburg garden, the Latin quarter, plenty of shops and restaurants and lots of nice walking streets.

1st link is second best location.