I wondered about that question when I read it too! Obviously there is a big difference between being with another person and using an object to stimulate one's self.
To answer your questions:
1. Is it better to use a dildo than to masturbate manually? It depends on the mood -- both have there advantages and disadvantages.
2. Is it better to use a dildo than having sex (ofcourse the performance of the partner is a big variable here, but I'm looking in general terms)? No way!
3. What are your thought on the use of sex-toy's such a dildos, vibrators? I enjoy using them to enhance my sex life. Often times they are much more fun to use with my partner than alone! I like using toys that please him as much as those that please me! I say, as long as it is agreeable and pleasurable for all those involved, use them!
4. Do you think it is natural/normal/healthy to use a dildo? Sure, why not?
5. Is it compareable to the use of an inflatable lovedoll? From what I've been told, no. I hear from my sons and male friends that the love dolls do nothing for them. A dildo does stimulate me.
6. Is it compareable to the use of a prostitute? NO NO NO
7. Could you lable using a dildo as cheating? NEVER
8. Do women use dildos as a replacement to sex? I think some could. I never would -- not with Lebell in my life!
A-matter-of-fact, I think if I was ever tempted to use it as a replacement that it would be a huge red flag that something is wrong with our relationship.