Volatility trended down, as the price trended up. No significant entry points for long positions in the RUT, in particular. If the market continues slow and creeping, weekly trades seem the best choice.
Gamma risk is high for near or at the money calendars. This risk can be controlled by putting a butterfly at the center and adding calendars on either side. This is more complex, however. The simple design will weather the difficult times better, in as much as transaction costs and time are lower.