The humidifier arrived in a nicely designed cardboard tube with a detailed instruction manual on the basics for setup and usage.
The humidifier itself is a decent sized reservoir that can hold over 10 oz. of water, and uses a sponge wick to soak up to the upper sponge surface. The sponge surface is covered by a gated screen that you can adjust to slightly open or close, theoretically reducing moisture release.
The humidifier did arrive with a fair amount of green foam dust spread across the top, from manufacturing most likely. While I did my best to wipe this off, you can still see evidence remaining. While this is not a problem for the functionality of the humidifier, it may be aesthetically concerning for some.
Build quality overall seems good, although some edges appear to be a slightly unaligned.
Upon initial filling, it did take a while for the upper foam surface to become completely moisturized, which does give a clue as to how slowly the water is dispersed. I consider this a good thing, as the main issue with passive humidification can be over-saturation. Even after it was fully moisturized, there are dry spots in some corners. Whether this is a problem (in the eyes of the user or the designer), I cannot say.
After nearly 6 weeks of use, the water level has gone down approximately 2/3rds. That to me shows a good, slow, and stable release of moisture.
As far as using the slotted gates to dial in the humidity, I wasn't able to achieve a notable difference, but the environment I was using this for might not be ideal. With a decent amount of cigars in the humidor, small changes might not be noticed for months.
While there are many reasons to choose a specific humidification system for every different humidor setup and preference, in comparing the Oshkosh Premium Humidifier with other passive foam humidification systems, I would have to rank this among the best. My main reasons would be:
It is not a solid foam brick. Many foam brick setups are prone to mold, but I think the design of this humidifier would make that somewhat less likely (though still a risk).
It has a reservoir. Traditional foam bricks are difficult to use at times, as you can accidentally let them dry out and damage your cigars. While that's a risk with any humidification system, having a large reservoir of water easily gives you months of humidification, and an easy way to judge how much water is remaining.
Used in combination with 2 way active humidification systems, I feel this method humidifier would provide a great deal of stability and longevity without introducing too much risk.
The main downsides of this specific humidifier, when compared to other passive humidification systems, would be:
Bulkiness of the device. I can update with the dimensions later, but it is a little longer (but shorter) than the Cigar Oasis Excel
Risk of spillage. If this device tipped over, water would be released into your humidor.
All in all, I think this is a good product that is being introduced to the humidification market. While many people can debate the merits of different types of humidification systems, if someone asked me to recommend a passive humidification system for a large humidor, I would probably tell them about the Oshkosh Premium Humidifier. For small humidors, there are better options. For those who argue the utility for a passive humidification system like this, I can see a lot of use in using it in conjunction with 2 way active humidification system.
I could give this a rating of 4/5, when comparing with competing passive humidification systems.