I've only ever seen abeka at a conference and it struck me as simply Christian but when I look it up on keepingitcatholic.org I find both abeka and bju listed under curriculums that have an anti-Catholic slant. I think you would have to decide for yourself if you feel this to be so after you look at it, I didn't see it but I didn't really take much time with it or look for it.
We use seton for a few subjects and as a supplement to other subjects for our preschooler and kindergardener (who's now into seton 1st grade materials now). I really like their workbooks, very well laid out and basic but still colorful and interesting. Please note that they lean to the traditional side. You child will also need to know or be explained some of the pictures (for example my 5.5 yo doesn't yet know that the man pictured with the pen is Luke, she just says 'man'). Many pictures need to be explained the first time they come up but there is a picture dictionary for the words the pictures represent in the back (for the phonics workbooks). I don't use their program because I don't want to have to mail in work to be graded. I would like if you could get the lesson plans without signing up for the grading but that's the only way to get them so we just use the workbooks and make up our own lessons. If you order more than $100 or so from them they send you the first four weeks of lessons for one grade level and they're well planned, but a bit short. I like how 1st grade and up have art appreciation (expect all religious art), it's nice to have art be more than craft time. I'm not crazy about their science books, for kindergarden it was a thin book with simple experiments like putting celery in water with food coloring. They explain what is happening with sort of long winded paragraphs about God making the celery, which is great, but then the scientific part seems too short. When we did the experiments I just used the book for ideas. We use real science for kids for scientific reading material the kids can still understand. The phonics and spelling books are my favorites, everything (even other books) are printed on nice paper in full color. It's a great change from some of our other workbooks that are black and white on newsprint. We use mathusee as our math program but like the seton math workbook for supplemental pages and for things like counting money that mathusee doesn't cover. I also like how the workbooks are fairly priced. Some workbooks, especially color ones, seem so expensive that I cringe when the kids write in them but with seton books I don't mind at all and it's not a huge expense to replace them all the following year for the next child. I think it's a nice boost for a child to receive their own brand new book.
