I had Poser 4 and while I miss some of it's things (ability to make hair in program), I have always used Daz Studio free version since Daz 3 and only regret the dynamic clothing but most of the freebies make up for it and I've heard of a way to get clothroom only clothing to work in Daz Studio.

The pro has a Gen4 to Genesis clothes converter (autofit)(which I've heard has problems with footwear).

It also has a content create thing somewhere in it. (I haven't own Pro for long so I don't know where everything is).

Overall I prefer Daz because it's free why pay 400+ for something if your just hobbyist and doing it in your spare time? Plus I haven't the money to thow away on a program every year.

It can search for item, but I've never tried it.

Plus there are great shaders for Daz, some free (at Sharecg) and others like Sparkles for Studio and Furify, which are very much worth it.

there's also fabricator, lacemaker and others which have a poser addition too (sold separtly)