Personally, I like the unit study programs. I used KONOS last year and will be using the Weaver curriculum this year. The Weaver curriculum encompasses K-6th grade, which works out great because I have two 4th graders and one Kinder.
Anyway, I like the unit studies because I can use one curriculum for all the kids. THe only thing that the weaver doesn't come with is a math and the KONOS you need a separate language arts and math program.
I've used the Alpha Omega lifepacs, which are a bunch of workbooks, a set of 10 for each subject and I liked using them for language arts, but one year I used them for 5 subjects and my older girls HATED school that year. I can't say I blame them though.
I will tell you that I've see Abeka and used Bob Jones and I do NOT recommend either program, only because they were made for a classroom setting and not so much homeschoolers.
I hope this helps you at least some. I'm thinking this might be your first year homeschooling. Good luck on finding the curriculum that fits your family. And just remember, what one curriculum might work great for one family, might be a total disaster for another family. I guess that doesn't help much, but because the diversity of kids and learning styles, that's just the way it is.