Speakers that do rock justice ...

consider magnepan 20.1. this speaker is minimally inaccurate, dynamic nad has deep enough bass.
try the non-cone solution. don't follow the herd.

Sorry Mrtennis - I've got the 20.1's biamped with 1400 wpc total power, and I still wouldn't say they are especially dynamic. They are alot of other great things - natural, spacious, tonally balanced, large soundstage - but I would not put dynamic on the top of the list of their strengths. I am still working on though - and with the new custom crossover (on its way), that may open things up a bit. They need A LOT of amplification - be prepared to spend at least as much as the speaker in amplification!

I think your choice of the PSB Stratus Gold is one of the best for the money and your requirements. Wouldn't suggest anything else unless you wanted to spend much more or would be interested in some old orphans like Infinity Kappa or RS series, Dunlavys or Hales. New, at twice the bucks, there are some nicer options.

A lot of people like to play pop/rock on their systems, but that doesn't mean one of the requierments is for the speakers to sound great loud, although it is fun at times. What about speakers that are good at rock, but also sound very good at mid to lower volumes? Also, how come some claim "audiophile" speakers are not good at rock? Is it something about their design or the way they are voiced? From reading the boards and tons of reviews many people with "audiophile" type speakers listen to a lot of rock music too. Why don't these people just go out and get Klipsch, JBLs, Paradigms, or other speakers that are considered "rock" speakers and save some money.

What about speakers that are good at rock, but also sound very good at mid to lower volumes?

There are a great many speakers to choose from at low to mid volume capability levels - most of them sound excellent. A good audiophile rock speaker will also sound excellent at extreme SPL's (the added capability). Whilst ordinary or low cost rock speakers may not sound very good at all (just play loud).

It is simply much more expensive to build an "audiophile" quality speaker that plays very loud. You may have to compromise on exotic wood cabinetry (expensive) and get an ordinary black box with pro audio drivers (expensive) that is all. An extra thousand dollars in manufacturing cost that would have gone to veneer goes towards expensive drivers instead of cheap ones ($600 woofer instead of $100 and $600 mid instead of $100).

Is it something about their design

Yes it requires a compression horn driver OR a super robust conventional driver (short coil long gap and huge magnets). There are specific design choices needed to play cleanly at loud dynamic levels, such as dealing with the high levels of heat generated in the voice coil (causes compression). If anything the speaker will be voiced lean in the bass, as bass sounds stronger at elevated levels but is nearly inaudible at low levels (Fletcher Munsun curves).