Hornbow used to be utterly fantastic, the obvious choice, but now I have to say the Rus wins out a lot of times due to the raw stopping power given how many people (at least on NA) use massive amounts of armor anymore and stack STR and IF.
Remember that those extra 3 points can stack up fast, as unlike PS which adds 8% per, PD adds 14%. So for me (8PD 166 wpf) shooting at someone with 40 armor:
MW Horn + MW Bods: Avg 33.4 Max 46.1
MW Rus + MW Bods: Avg 39.7 Max 53.5
Enough to make me happy.
Besides, the Rus Model looks better and sexier to me then the Horn. It is really personal preference.