I don't want to get into the rear speaker debate again (there is a separate thread for that) but if you have your stereo configured correctly then people in the back seat will hear the highs just fine. Even with kickpanel speakers the sound will make it to the back. If people are complaining about too much bass...chances are they are correct and you need to turn down the sub.
As for JVC. I did a little more research (as in I looked up their flagship model). They are definitely a few steps above Jensen. However, most of the features on the flagship come standard on the top 3-5 Pioneer, Eclipse, Clarion, and Alpine units. The pricing is in-line with comparable products from the other brands but they don't have anything special to offer. They don't have the features that make or break a high-end competition system. However, I like the look and they have some interesting designs and a full product line (including multimedia).
JVC will become a big contender but they will never make it to Alpine status. No one has touched Alpine for as long as I have been watching the car audio industry and I don't think anyone will. Alpine knows how to sell to the entry-level market and they know how to stay on top of the latest technologies and offer cutting edge features on their top models...and they can do it across the board (head units, amplifiers, speakers, multimedia, etc). Unless something drastic happens they are going to be a front runner for a long time.
