I'm really on the fence between the m lores, a3rx-c, and Denton's. I don't really see any better options than those three and they all sound like they have pros and cons.
I heard the arx and would NOT put them in the same class as the dentons, the dentons are a modern retro speaker and well made, if you were closer I would have no issues letting you come by and take a listen, I have a luxman l505ux integrated running a set, the system does more than just look AWESOME, everyone that hears it is taken over by how airy it is, sounds like it costs A LOT, lol...
For the arx, I can't say I paid much attention to them but they sounded "jumbled" like they were not tuned correctly, not sure what the graphs for these things looks like but they sounded all over the place, I was not impressed with the bass, what do the specs say? The dentons dig for a book, they look small in the pictures but its a good sized speaker...
Heres the things that would sway my decision, Say in 2 years you want to upgrade or move on,
1-bookshelfs are easy to relocate to a bedroom, I have a set in my dining room on a hutch you barely notice them, and they are classy enough to pass as belonging there.
2- resale value on the dentons will stay strong, what will happen is MD will sell out of them soon (I was told they have 2 sets left, the other day when I was talking to Mike) and then you will see them used for what MD was selling them for on sale, if not more, it happened with the epos epic 2's, the wharfedale opus line, and others... The other factor of resale is, it is easier to ship bookshelfs than towers so less of your money goes to UPS...
3- IMO the dentons have a memorable sound, they are definitely strong enough to stand alone with out a sun in a decent sized room and enough power behind them with almost all genres of music, some R and B, Rap, and electro stuff with synthetic bass is tough to keep up with for a book shelf, I will admit that, but that is for all bookshelfs, and it will apply to EVERY 2 or 3 way tower in your price range, except your insufficient lows will be accompanied by some less than mediocre mids and what I would call a barely satisfactory high end...
I would jump on the dentons, they are a great speaker for the price, I would say they were a really nice speaker when they were $999, sure for the $1000 mark there are more accurate speakers available, BUT NOT better looking, and you will need to go to ID company to start to compete...
If you are still not sold on the dentons, the other speaker I would look at is the cbm170, but that is just a black box, for the money its also a great contender, I have a couple pairs of them also....
good luck...