Propower crunch bench, any comments?

I'm getting ready to plan to buy propower equipment slowly for my home gym in the future. One thing I am debating is the ab crunch bench. On another site everyone just told me to buy a ab wheel (and I did). It works the upper abs quite a bit but wonder since Hatfield possibly designed and sells the crunch bench with resistance bands if it is neccesarey for a complete abdominal workout. I've been told a crunch bench works mostly lower (if I remember correctly) so perhaps the ab wheel goes well wtih it to do upper. Honestly, the best device I have used was the ab rocker floor device sold at most k-marts but I never tried propower's bench yet.