Hi,
Just to clarify, writing to the PORT registers still works on ALL devices. The thing is that newer devices can run much faster (64MHz) compared to older (20MHz) so the risk of running into RMW issues are bigger.

Using the LAT register (when available) for outputs is a good idea. However, I'm not entirely sure that using HIGH/LOW (or any high level pin/port command) on LAT works, actually I don't think it does, but I'd be happy to stand corrected on that.

/Henrik.