Do different Ivy's look for different things?

Hi

I’m an international student hoping to apply to Ivys later this year and am wondering how beneficial it would be to hire an admissions consultancy firm to help with my application? I’ve been in touch with a couple and what they told me was that one of the things they do is help cater my application to individual colleges; ie that different Ivy colleges have different preferences and that you cannot simply find this stuff out on the internet. Is this true? Or do they all look for generally similar stuff?

Cheers