mega168 vs 168p?

[justDIY]

In my ignorance, I ordered some unsupported mega168p's to mess around with on the breadboard, instead of the supported mega168 I used the -F force option to program a hex which was compiled for a m168, and it runs on the 168p ... is there anything I should worry about down the road?

[adafruit]

should be OK, i believe the only differences are power consumption during sleep modes

[kscharf]

Atmel may eventually discontinue the non "P" parts for which "P" parts are now available as the "P" versions should be drop in pip for pin replacements.

Some new parts are also being given "A" suffixes such as the tiny13A vs the tiny13. In both cases the newer parts have refined process that reduces power consumption (die shrink and metalization changes). Some parts also have new register bits for advanced control of power down but the default settings of these are backward compatible with the older parts.

Of course if you are manufacturing a product using these parts you will want to qualify the new parts before shipping product with then, "just in case".