433Mhz vs 900Mhz
 

So I've noticed that many top end alarms being sold in America are leaning towards 900Mhz frequencies while the same Canadian models are using 433Mhz. What's the drawbacks between using one versus the other?

900 Mhz is like a home phone. How far does it work?

The 433 that Compustar uses works up to 5000 feet away. My home phone won't do that.

So if that's the case, why is something like Compustar's top end Pro models 900Mhz while their base models are 433? Or am I missing something?

http://www.compustar.com/main.htm will give you the American information. It won't tell you how much better the FM 433 is. The 900 American model gives you 3000 feet of range, while the FM 433 (International) gives you 5000 feet.
I was told by my rep that their FCC rules won't allow it. Canada's will. We get better range.
The AM 433 Mhz product is available to everyone and has a smaller price point.

Just like the am and fm frequencies on your radio, lower the frequency will give you further distance but less clear, and higher freqencies will have less range but better reception.

Thats why AM stations can be heard from a further distance than that of FM, they have a much lower frequency band.

through the years of having many cars and alarms put in them, sure the the 433Mhz will give you better range, but doesnt travel through walls very well. 900Mhz band may be a shorter distance but if your parked at a mall or some place like that, your reception inside is better.

just my 2 cents.