Some of the answer to this depends on what type of environment you live in. The house I live in is completely open, with the bathrooms and closets being the only real doors in the house. The bedroom has a pocket door. Due to this open architecture, when I'm cooking, stuff is floating through the air that could get on the guitars if they were hanging on walls or sitting on stands, even if in other rooms. Same applies to other airborne particles. If you have a room devoted to your equipment, then this is obviously not a problem or at least significantly reduced. Another factor already discussed here is humidification. I have been using the Boveda packs for about 6 years now and really like them. As mentioned, they are bi-directional meaning when humidity is low, they add moisture to your case, when humidity is high, they absorb moisture. Another factor is light conditions. If you have direct sunlight in your space, that can wreak havoc on just about anything, so be careful of that. Any excessive light exposure can cause problems, especially for organic dyed woods. I keep all mine in cases and I wish I had a space where I did not have to, but current conditions are what they are!
