the mrs is quite fond of her "toy" (solo as well as incorporated into our fun which we typically do to make sure she gets off), but claims it doesn't cut into our sex life (which is just a romp or two a month shy of being perfectly adequate for me). on average, if you're hitting the vibrator and climaxing, how soon might you be ready for some partner fun? are you satiated for the day, a couple days...? I can tell when the "back massager" has been unleashed from storage and I swear that equals no sex for a couple more days. she says fulfilling the need with a vibrator is completely different than having sex--I say "hooey"!
Playing with a toy is different than playing with a partner, IMO. However, she could be one of those people that likes to get her fix every few days. Realistically the vibrator could possibly affect your sex life. You could always incorporate it into your sex play if she's willing? Not trying to talk you down, but maybe she's not always getting what she needs from sex so she's using the vibe?