It's slightly frustrating to come back to the game and find a fun or crazy build being used that is used older mods that aren't available as rewards anymore. The frustration comes from the only means to acquire them is to purchase them from a vendor who randomly rotates through the mods. My main complaint here is the rotation scheduling. Ada offers 1 combat mod a day but she could list the same mod every day in a month, or frequent the same limited mods without ever selling a mod not previously sold. I'd like to see older mods added to a Playlist as a reward, Ada offer a way to exchange materials for a chance at a mod, bounties to get the mods as a reward, or have Ada sell more than one combat mod a day and utilizing a system to force her to rotate through mods. Not all of these solutions are needed to address the problem. The bag system would be ideal in my opinion and would give incoming players an idea of when a mod will become available. Even if you'd could grind out materials and turn them in for a chance, it would at least improve the odds of being able to get a build going. The reason I think this is an issue, is for any player who missed the mods, can't do some of the builds shared on the community or used by community leaders until they get all the mod pieces. As it stands some players may never be able to even try a build or grind to get the build they want to use. I know people in Destiny aren't leary of a grind or grinding systems. The existing system is purely RNG and no amount of grinding changes what's available each day.