The 511 link you have is about $40 more than other sellers such as Amazon.
The issue with FRS is that you are limited to 500mW 0.5 watt transmission meaning your range is if you are lucky 1 mile or with sufficient elevation perhaps 2 miles, however a city block is what you might expect. If using high power GMRS mode you have more power on your transmission, same as CB more or less but at a much higher output, at 4 to 5 watts. Bear in mind a GMRS license costs something like $85, the FCC is considering removing the license requirement and instead just using license by rule rather than registration like FRS and I think CB.
They could be useful for communicating in instance where being loud may not be beneficial such as yelling for someone, or in an urban environment where walls or rooms obstruct people.
Of course they can be useful, however in general getting your basic ham license will open you to more possibilities. FRS is short range don't expect more than a mile, if even half that depending on environment. In GMRS mode you are probably paying more than you would to get ham certified, and radios such as the baofang UV-5R or others can be picked up for between $30 and $50 with 4 to 5 watt output same as the GMRS setting, but with your ham liscense you will have a much greater potential.
It costs more in the US than Canada, basically completely free for me to get my basic with honours and advanced certifications, now there is a massive array of communication options, and I can even build or modify my own.
The big plus on the 511 is that it has a crank and acts as a charger for other midland devices and it has a mic that can be used on other midland products (which is $10 to $20 transfer value, and of course it is a clock radio with a light, which can be useful. However they sell for $70 so paying $110 is paying more than you need to. I love the hand crank.
I opted to get my ham certifications, imo, it was the right way to go because I can buy or build pretty much anything now, and can operate at 1000 watts. (in the US at 1500 watts) which is more than enough power to communicate most anywhere.