Looking at the Select category of Marriott brands, here's their view of the competition:

AC Hotels:
KEY COMPETITORS
Hotel Indigo, Canopy by Hilton,
Kimpton, Public, Joie de Vivre,
independent boutique hotels

Aloft:
KEY COMPETITORS
Hilton Garden Inn, Hyatt Place

Courtyard:
KEY COMPETITORS
Hilton Garden Inn, Hyatt Place,
Holiday Inn

Fairfield:
KEY COMPETITORS
Hampton Inn
Holiday Inn Express

Four Points:
Key Competitors
Hyatt Place, Hilton Garden Inn

Moxy:
KEY COMPETITORS
Citizen M, Tommie, Generator,
Motel One, Pod 39, Mama Shelter,
Yotel

SpringHill Suites:
KEY COMPETITORS
Hyatt Place, Hotel Indigo,
Hampton


David