Do it, and install the following:
http://www.moddb.com/mods/deus-ex-new-vision for improved graphics. If you have a modern graphics card and windows 7, you can also use the Direct3D10 renderer that comes with it. Otherwise the OpenGL one.
http://www.moddb.com/mods/biomod for some cool gameplay changes. Makes the augs more useful, by turning some of them into passive ones that only drain energy when they're actually doing something, like toxic resistance. Same for hazmat suits and body armor. It's based on the popular Shifter mod too, taking about everything from it besides the XP rewards for takedowns/kills.
I think HDTP is currently incompatible with Biomod, but the current HDTP release (same one as 5 years ago) doesn't replace a whole lot anyway.
http://i.imgur.com/wGz4I.jpg
Deus Ex never leaves my HDD.