Clifford Alarm. Solaris? And how much?

Hey guys, I've posted in previous threads my desire to get an aftermarket alarm system because we all know that the factory alarm is worthless.
I have decided to go with Clifford and I was going with the Solaris with prox sensor and extra siren until today. Best Buy in my area told me that there is a new alarm called Matrix RS2 (It pretty much "replaces" the Solaris or something like that...)
In my area, there is pretty much only Best Buy (which opened about 2 weeks ago) and an independent retailer. I found out that there is a huge price difference between both companies. I was going to get the solaris installed at that independent shop in 3 days (they needed the car for two days... which sounded kinda weird...) but cancelled for many reasons. First they are about $150 more expensive than Best Buy and I don't know how well their installers are. I was told they were certified but i don't know by whom.
I have several questions to ask.
1. If you guys have a solaris installed, what was the price (ball park) of the system plus installation?
2. How good is their prox sensor?
3. Is it worth to put an extra siren? I want that because my car's been messed up with in the past month twice with the stock alarm and I don't want that to happen again.
4. How good is Best Buy? I guess that's not a good question because it all depends on the installer and not the company, but are all installers certified? And how well are those certifications?
I am especially interested in the first question because I feel like i'm being ripped off (although I already cancelled the appointment) at that shop...
Any feedback is really appreciated.
Thanks guys.
Oh! If you've had bad experience with Clifford, i'd love to know that too.
Giancarlo.