1) Some paper manufacturers have a reputation for providing very high quality profiles with their papers. Personally, I have no interest in adding in the additional complexity and expense of profiling paper myself.
This is a big deal. I started using Exhibition Fiber when the price came down and use a PixelGenious profile for it rather than the one from Epson.
2) Price is a significant factor for many of us in the decision of which paper to use. In general, Hahnemuhle and Moab are simply too expensive for me to be comfortable using for my personal printing no matter how serious I am about it.
Concur that in general, the Hahnemuhle papers are fairly pricey. For value on an Epson printer, almost nothing beats the Epson Papers. I hate the flimsyness of the Luster 260, but it has a wonderful surface and is really inexpensive. The Hot/Cold Press Bright/Natural are also great papers for the money.
3) Texture or surface is a big deal. I don't simply mean matte versus glossy.
Yeah, this is an area that people start writing comments and mixing surface texture with sheen. You can have matte, luster, satin, pearl, semi-gloss and gloss on a paper while the surface can be from smooth to highly textured.
My recommendation is to buy sample packs (remember when they used to give you decent size sample boxes of different papers for free).