I can report a very good experience with a pair of Alto TS415's:
I inherited the duties of setting up and operating the PA for my band after we lost our ringleader and his PA gear a couple years ago. We got by for a while with using an array of rinky dink equipment (heavy passive mains, power amp, lots of speaker cable...), but I wanted to get a half-decent mixing board along with a capable set of powered mains that would be easier to live with and also (hopefully) deliver all the sound we needed. There was a bundle of strong reviews out there for the powered speakers from QSC, but I didn't want to spend quite that much money to make a solid step up with our sound if it wasn't necessary.
I found a nice deal on a 16-channel Mackie analog board that included six monitor channels (a plus for our situation) and after researching and looking around at different powered mains, I bought a new pair of Alto TS415's. The specs on these seemed to give them the edge over their TS412's in terms of overall performance, freq response, yaddah-yaddah, and I liked that because I didn't want to also go shopping for a powered sub, at least right away.
Bonus points: I found my Alto's on sale and also had some stuff to trade in at GC, so I got a nice deal on them, which included their full replacement coverage for a year or two (don't remember).
I don't have a ton of PA experience with a dozen different brands or anything like that, but I can say that the bang for my buck that I've found with my Alto speakers has been a very pleasant surprise. Pals of ours from a couple of other bands have heard them on a couple different occasions and have offered high praise both for the quality of my mixes as well as the terrific sound that the Altos put into the space.
Earlier on, we also borrowed a pair of Harbinger 4112's for some shows before using the passive mains that preceded these Altos and those Harbingers also worked nicely for us for the shows where we had them. We run all our vocals through our mains along with some kick drum and I've also been adding some of my bass sound to the mix so that I can be a little less noisy with my stage rig. I was nervous about the quality of my DI sound through the PA, but its warmth and clarity is great for the material we do at moderate levels. Translation: my bass sounds nice through these mains.
Everybody in my group also uses powered wedge monitors - no IEM's - but I'm having trouble convincing the guitar guys to put more sound through the PA instead of using loud amps on stage. Other brands and/or models of speakers might have some attractive bells 'n whistles, but these Altos have been issue free for about a year's worth of shows now, they're easy for me to set up and transport, and their sound has been big and yummy without breaking a sweat.