Fun historic trivia on TPS and SHS:
TownePlace Suites was developed in the early '90s when Residence Inn's rate structure began to get so high as to exclude some core long-term stay business - most particularly, government business. Marriott decided to develop a "Residence Inn Light" concept that would have a lesser finish level, occupy a smaller real estate footprint, have lesser amenities (small pool, no Sport Court), and re-attract government and other long-term stay business that had been priced out of the Residence Inn market. TownePlace Suites #1 was built in Newport News, VA, in 1997.
Another way TPS reduced costs was in the labor area. The original concept had only 7 FTEs (full-time equivalent) on staff - 1 GM, 1 sales, 2 front desk, 2 housekeepers, 1 engineer.
SpringHill Suites is the death and re-birth of Fairfield Suites. With Fairfield Inn's success in the '80s, and the all-suite hotel push around 1990, the thought was to create a brand "extension" of Fairfield Inn and call it Fairfield Suites - an all suite, economy product. It didn't work - Marriott found that the all-suite product was horribly underpriced for the value it gave travelers. Marriott killed the Marriott Suites product, reworked the floor plan and room plan, and launched SpringHill Suites in December 1998. (Today Fairfield Inn & Suites exists essentially as a separate model or floorplan of Fairfield Inn, but that's another story.)
SpringHill Suites today is much more like what Courtyard would have been created as in the late '90s (instead of 1982, when the first Courtyard was built in Atlanta). It is an all-suite product with pool and exercise area, continental breakfast buffet in the morning (included), but no other F&B. However, there are still echoes of Fairfield Inn at SpringHill Suites - when you check in, you are presented with a registration card that, save for the purple ink and the SHS logo, looks exactly like a Fairfield Inn registration card.
So, TownePlace Suites is essentially Residence Inn on a diet... and SpringHill Suites is Fairfield Inn on steroids.