I personally think theyre awesome cabs for the price. Nice, full, chunky sound. And they can CRANK. I fully support Behringer cabs.
By 'good' I assume you mean for the price. It uses no-brand speakers.
Its likely one of the cheapest 4x12s available and for the price its likely delivers well.

If you are set on a 4x12, its more than likely you can find on ebay/craigslist a cab with Celestions (V30s,etc)

Look into used Marshall 1960A/BV's, Avatar G412s, Mesa, Peavey..etc
1981 Marshall JCM800 2203
Mesa Boogie Tripple Rectifier 2 Channel
Avatar G412 4x12 Vintage 30s
Sobbat Drive Breaker 1
Mine is an older one. It has Jenson speakers. Which are a WHOLE LOT better than the speakers theyre using now...
I'd stay away from Behringer, they are one of the most notoriously unreliable companies out there. Their old European stuff apparently used to be good, but nowadays they have shocking build quality.
"You can practice to attain knowledge, but you can't practice to attain wisdom." - Herbie Hancock
alright well what do you guys recommend for a 4x12 cab that is cheaper but has good quality?
mm i dont know

why would you need a 4 12 cab anyway? all it would do is push more directional air. What you need to get is somethign to elevate your combo (im assuming the flextone III is in combo format........if its the head, then totally ignore what im going to write next), so that its pointing closer to your ears,

pass on the sub par cab, behringer make some decent rack mount sound processors, and some pretty good mixers, but they are cheap, adn you get what you pay for, and with amps and cabs, they havnt had a good rep. Go for it, but its really not worth the moneys,

Gibson Les Paul Studio w/dirtyfingers pickups
Gibson Joan Jett Melody Maker
VOX ac30 head
Marshall 1960 4x12 cab
Fender Hot Rod Deville