I would be cautious of just buying a brand without understanding the various models and what they come with as standard features. A good example is the WEG CFW300 VFD drives, only the B frame size models have provisions for an external braking resistor, so the 2 HP single phase CFW300A07P3S2NB20 does not have this ability, the 3 Hp CFW300B10P0B2DB20 does have this ability. The standard WEG VFD model only has 4 inputs, which can be very limiting if say using are using 3 wire control which takes up 3 inputs, then if you want to jog, fast stop, change the braking speed add another speed function, you do not have enough inputs. There are optional modules to add more inputs, but at an additional cost. The 3 Hp single phase input CFW300 VFD is derated for higher carrier frequency so a 3Hp 10A model is derated to 8A for a carrier frequency of 12-15 kHz. The Hitachi WJ200-15S and -022S are not derated so the 2HP WJ200-015SF at the higher carrier frequency has the same current output as the 3 Hp WEG. A few other gotchas, so you need to know what you are comparing as far as features and your needs. OK for a basic mill install, wouldn't use it for a lathe install. You will see a lot of Hitachi WJ200 used along with Yaskawa drives in factory installs for mills and lathes in the 3-5 Hp range.
The Automation Direct GS2 is a very dated design and pretty simplistic (like not having sensorless vector control), there are better drives out there these days. Their GS4 model is expensive.
As far as braking, an external braking resistor would be needed if a mill is in back gear and you wanted quick stopping for tapping, in the high speed gears you should be able to get 3-4 seconds w/o a braking resistor. Controlled deceleration requires a braking resistor, the speed/rate is enhanced with an external braking resistor. Also in an emergency E-Stop or Fast Stop command. All the factory installs that I am aware of do have an external braking resistor. In a lathe it is required. Cheaper VFD may have poorer braking abilities due to cost cutting in the design/components, better VFD's have better ability to control an over voltage buss error from too rapid braking which causes you to loose all braking. I deal with installing the drives not how they work, others can provide more details and opinions. I personally stick with the Hitachi WJ200, Teco A/E510, Yasakawa V1000 drives for installs in the 1-5Hp range.