Search this forum, the topic has been covered in detail but can't remember the exact name of thread. I had a bad Harbor Freight one right off the shelf. Took it back for a refund. But I still have two other H.F.s that work. Some folks swear by um.
I assume you mean the Bar-Rail type when you say 'scale'. The Bar Rail is the most economical and totally reliable since they don't get out of calibration. But they are hard to read upside down or sideways. If you were rich you could buy a Dial reader which from what I'm told does not have to be recalibrated either.
If you are not rich the easiest to work with is a clicker type. No matter which brand you work with check them when you buy them, and check them periodically afterwards. And if you drop it, check it two or three times before you use it again. If it's bad, you have 2 choices, throw it in the recycle or have it recalibrated. Nowadays (unless you work in a pro shop) the availability and costs of calibration is more expensive than just buying another wrench that works. I have 2 Harbor Freights that check within 2 ft. lbs of my Sears. The Sears works like a cadilac compared to the harder twist H.F.s but it cost $122 as opposed to $22 for the H.F.s. But they all (the clickers) work unless bad, so check them.
I check mine like this. I bolt a 1/2" or 5/8" bolt to my truck trailer hitch mount. I torque it with one wrench to say 20 ft. lbs. Then I set another wrench to the same setting and try it. If the bolts moves before it clicks, I then set the original wrench to 21 ft lbs back on the bolt. I keep trying and keep turning the dial just a tad until it moves the bolt again and note the difference.
In the reverse is the wrench being checked did click before moving the bolt, I would keep moving it's setting up 1 ft lb until it did move the bolt just to make sure it wasn't clicking too low.
If you use a torque wrench often, you will probably get more use out of higher price one before it goes out of calibration, but for weekend wrenching you will save a bunch with a H.F. and still a some with a Sears since a Pro Snap will cost you from $250 up. And for that amount of cost you can buy several H.F.s and still come out ahead. But the thing to always keep in mind is CHECK THEM periodically or they can ruin something.