As a Hilton->Hyatt switcher myself, I've been very glad I switched. But to compare:

• Hyatt Place is on par (pricewise) with HGI, with nicer rooms -- but only cold breakfast is complimentary for elites.
• Summerfield Suites is comparable in pretty much every way to Homewood Suites. I'd go so far as to say "indistinguishable."

The big differences to me are the great promos and bonuses (read up on G1/G2/G3 bonuses and welcome amenities, and how to make sure you get them), and significantly better customer service. You'll also have better redemption options (in my opinion) when trading in the points.

Keep in mind at the mid level (Platinum), breakfast is not complimentary, as it is for Hilton Gold. However, it's included to some degree at Hyatt Place and Summerfield Suites anyway. And it's free at full service Hyatts and Andaz for Diamond members.

However, there are not nearly as many Hyatt hotels as there are Hiltons -- so be absolutely certain they'll actually exist where you need to go.