I picked up the 2031a monitors when I bought my first recording setup, I wanted to maximize my $$ going into that initial purchase, and I'd read quite a few reviews saying these were the best in the price range, so I went for it.
I'll start by saying these things sound really good. That's not to say that they are all accurate, just that they are pleasurable to listen to music on. They can get very loud and rock out, and will get a good thump going on if you push them.
Starting off, they worked well through the first few years of my learning, I didn't have a treated room or many othe rpieces, so they were more than adequate for doing some simple mixes. After treating my room they became much more functional, and I started to really dial in what works and what doesn't on them. As my ears have matured, I've found the limitations of these monitors. Often I have a tendency to mix bass too loud, or have phasey stuff going on, presumably from some imaging issue. Lately as I've started to really hear subtleties more, I've been annoyed, often feeling like I'm not getting very accurate information.
I'm a few years into this recording journey, and I feel like I've just recently reached a point in my skills where I've outgrown these monitors, so I'm eyeing a considerable step up to some Adams or Focals or Neumanns. But, I will say, these monitors have been consistently fun to listen to and accurate enough for a beginner to intermediate user. Eventually if you keep at it, your ears may outgrow them, but they will certainly do as a decent entry-level set for someone relatively new to nearfields and recording in general. Probably about as good as you could do under $500.
These are really handy self-powered speakers and they have held up really well. I have a pair of Mackies in my studio, and decided to try these out for live monitoring of my keyboard rig. They are the answer to achieving a really happy experience live. The problem with keyboard amps that I've always dealt with just by gritting my teeth, is that they sound ok for some of the grungier keyboards, clav, some rhodes etc., for the more hi-fi acoustic instruments, like for acoustic piano, strings, brass, etc. they sound honky and unpleasant. The powered PA speakers are pricey, so I just screwed a couple handles on these monitors and carry them to my gigs, they have been great. They have never failed and sound terrific. Just like my keyboards sound in my studio. So I highly recommend them for this use as well as in the home studio.