We've done WP's Animal Worlds. My dd liked it, I didn't because some of it was scattered. You'd be talking about an animal location then out of the blue, you'd be doing something for an animal that didn't fit to the area at all

, but yet it could have been matched up, which was wierd. The "other" animal was just put somewhere else that didn't match up with that location either. Just not quite perfected IMO. Being very organized, that drove me batty, along w/a lot of typos, which is even more of an issue with me. But it doesn't NOT make it a good program. Reading is in snippets, because it's literature-based. So you're reading a page or two in 3 or 4 different books which to me screwed up the flow, however that works for some. Many people just read one book one day, then another one another day. My thoughts are that I shouldn't have to rework an entire curriculum for that price or deal with typos and wrong page numbers or partial shipping issues on a grand scale.
WP AW is science, HOD is complete. WP's activities my dd liked, but they were straight from a book and some supplies were hard to come up with, some didn't work out, but again, my dd like the activities. HOD's activities are whatever you have at home, however less time consuming. WP is not bible integrated and doesn't contain any character training or "real" bible training other than the devotional book. You'd have to do that on your own along with all other subjects if that's an issue for you.
These are two completely different programs, so comparison is difficult. You're spending $350? for Science only and if you're good and able to do other subjects on your own those are above and beyond the price. HOD isn't integrated so much that you can't do portions of it. In fact, you could do WP AW for Science if you desired
and HOD.
I loved the thought of AW, but it just didn't work for me. Unit study means unit study and I ended up having to rework a lot of it and a lot of people do unless they didn't mind the ideosincracies.(sp?)
We did fast track phonics and NONE of it had anything to do with the "sound of the day" so-to-speak. So that was weird. We did the Pre-K basic phonics, but then I had a book that was never used, because they forgot to add the "new" book into the old teacher's guide. That was $17 wasted.
It is a good program, but there are many wierd things about it. IMO I wouldn't use it as my main curriculum, but I would like it for a science program or history program even though I know I'd have to rework it. But that is totally cost prohibitive, since it's such an expensive program. They also don't quite have their shipping down. Books are always on back order or discontinued and it's rare that you get your "box day" in full. Some wait months for books or the rest of the program. I'm not sure if that's an issue with other companies, it hasn't been with SL (we used Pre-K) or MFW. But HOD man...fast ship and it's all there!!!! They are fantastic.
So it's really about how and what you are interested in teaching, do you want a complete curriculum or a science additive...all depends on you and your child. The things I mentioned above, people just don't mind it. Personally, I though it was a lot of money for the amount of problems I had with it.