As a newb I got a SRD modular paddle strop mainly because I don't have a place to use a hanging strop.
Leaving aside the issues of whether a hanging or paddle strop is best the SRD modular paddle has the advantage that you can simply buy a replacement panel if you nick up the strop while learning.
I also like the fact that the basic set comes with 2 x wool felt, 1 x rough leather and 1 x finishing leather and diamond paste so you get the full set of all the strops you'll ever need in one purchase. And if you feel the need to upgrade/mess about with new toys buying a new panel is cheaper than buying whole new strops.
I can't really comment on whether a hanging strop has advantages over a paddle, but the SRD modular is a very well made bit of kit that is easy to use, is very versatile and you can upgrade/replace damage as and when you need to.