This review covers four recent flights on GOL - BSB/SDU, SDU/POA, POA/SDU and SDU/GRU.
All flights left on or slightly before scheduled departure time. Complementary on-board service is minimal - a glass of water and small bag of chips - but for a short flight that's fine. Additional items can be obtained for an extra charge, but I didn't see anyone ordering anything.
The aircraft (B737-700 and 800 Series) were clean and relatively new; all had a single class configuration, but the first few rows are designated as "GOL Conforto +" and these offer additional legroom. It costs a little more, but also provides priority check-in and boarding, and first-off baggage service. With the extra legroom the flight was, by contemporary standards, quite comfortable. The cabin crew and airport personnel were uniformly friendly and efficient.
GOL is a decent, reliable airline and generally offer the best schedules if you are flying domestically from the downtown airport in Rio (SDU).