I bought two, LegioLXX11, but I may buy some more so that I can follow my usual policy of keeping a couple boxed, and also adding a couple to my free-floating AFV collection which is a mixture of everything available in models over the last 20 years or so, as well as fully-builds which I've collected ever since I caught the CDC bug!
I agree that the Dragon S.P. gun collection: Hornisse, Hummel and Nashorn are all great opportunities for modellers to add their own detail.
For those of you who are scared of the idea of painting 1.72 soldiers, check out the advice and pics given by Mr LegioLXX11 and others on the Mini. Figs thread. I strongly recommend " Armourfast's" 1.72 Mortar Team and also their " Machine Gun Team". Both these kits will give you many figures to populate and bring to life the Dragon S.Ps in the uniforms of the 1943/4 period onwards.
Also, Pegasus' set,
" Mortar Team" will give you figures more suited to campaigns before 1942/3.
Even some basic painting of these figures: uniform, boots, leather strapping and flesh is enough to bring them some animation and add something to the character of the collection which you have spent days tracking down and aquiring. A figure or two, used judiciously on an open display, or even in a display case will add a new dimension to your collection.
If you want to spend a fascinating few hours finding out what is available check out the best site for 1.72 fig.s in plastic. The site is huge, but they do list sets in eras and by nationality. You can find painted examples on this site which I hope will give some of you ideas! :
http://www.plasticsoldierreview.com/ 
These figures will also enhance the appearance of your 251 collection of Dragons and FOVs. Preisser make figures for 251s and they look brilliant on the Dragons which I have. Think how the inclusion of a few figures with the FOV U.S. Half-Track made a distinct improvement to the appeal of it!
MoMo