If running the gym bag option, you will want your tools in pouches or rolls to prevent the bag from tearing out. Depending on how much tools you plan on carrying, the bag could get heavy real fast.
This would be an excellent “stealth” choice if you don’t want to advertise your are carrying tools or expensive electronics. The only negatives I can think of is that the fabric tends to be a lower denier nylon. Tool bags tend to be denier 500 or higher and are less likely to tear or split the...
Take a look at Bucket Boss. They have a variety of sizes and styles. It now looks like you can get them in traditional brown and green or gray and black. My gatemouth jr. and long boy bags have held up well over the years.