My set arrived today and I did a small review on the blog, but here's the essence:
The four sets:




(this set comes with a Bar piece as well)
There is a small insignificant size variation within the range:

Nothing major IMO - but will probably make some of them more or less useful.
And for the "scale fascists" (like myself)

Compared to what I have laying here:

Thats an old Citadel LOtR Frodo, Hasslefree, Heresy, Foundry, Old Citadel C-Range Halfling, Darkling Games, White Knight Miniatures
Couldn't find my box of GW Imperial Halflings (quite wonder where those are) - but should give you a good impression.
Last, the only bad thing I can think of was the little handwritten message on my invoice that said: "at present we have no plans to release more Halflings. We hope you enjoy these four packs, though" - quite a bad decision, if you ask me :-(