Many manufacturers offer various designs and versions of Tactical Clothing. As with most products available on the market, it can be a game of give and take. Variations can range from Military Wear, Executive Protection, Every Day Wear, Inclement Weather, etc. The important thing to recognize, is that almost all of the clothing is designed around particular usage, and are best employed in those specific roles.
The greatest benefit Tactical Clothing provides, it is designed with numerous pockets, allowing the wearer to carry tools and equipment comfortably, facilitating easy access to them throughout the course of a day. In some cases, it can offer protection against potential injury or weather in extreme hot or cold climates. Tactical Clothing can also include reinforced pads, stitching, and materials to better protect the wearer.
The main issue that arises with Tactical style clothing is that it can stand out sharply when worn in a public setting. For example, the general populace views a typical pair of khaki cargo pants and polo style shirt as being associated or affiliated with any number of various Law Enforcement and Military Agencies alike, and can indicate that the wearer is likely carrying tools, a knife, or even a concealed firearm (so much for being covert). Another major downside commonly overlooked, not all clothing is made in the U.S.A. Outsourced clothing's resistance to wear and tear from everyday usage, can be significantly less than the expected from the time the item was purchased. Finally, consider that while many items may get advertised as "covert", the fact that it is advertised does not make it so!
In summary, as long as the clothing is utilized for the purpose it was intended and designed for, the average user shouldn't run into many foreseeable issues. Especially, if the user understands what the clothing was created for and stays within those boundaries.