Is this a superior alarm?

I know from reading other posts here that the alarm is only as good as the installer. However, I live in the car theft capital, N.Y.C, and I was touted that Clifford alarms are inherently superior to Viper, Prestige,and Python, etc. The prices vary for the Clifford 6000 from $400--$350--$299, Viper is $249, Prestige is $199. Any suggestions would be helpfull because I am at a loss to decide. Thanks.
R.Q.