Warmtone paper tones better- you can access a bigger range of tones, and you can do it quite easily. Untoned, it is not really all that warm- you might expect from the name that it'd look sepia, but this is not the case... unless you sepia tone it. Untoned, it is slightly warmer (noticeable mostly in the highlights) than the non-warmtone paper.
If you are interested in toning then warmtone is a good place to start. You could get some sepia and selenium toners and do a series of split-toned prints from pure sepia to pure selenium, and then you'll see what warmtone can do. You can also tone it quite cold too, by the way.
Glossy is, as you know, very reflective and wet looking; pearl and satin less so.
Multigrade versions of all of these are available, which means that you can print them at different contrast grades and also do split-grade printing (sequential printing with two multigrade filters). Just get yourself some paper and a pack of filters and enjoy all the possibilities.