Vipers don't suck, installs might suck, one unit might be faulty.. overall they are under Directed and very good.
I have a 5901 or whichever one has the one mile with the black and white two way remote. I installed it myself, soldered every connection and went the extra mile to ensure it would never be an issue. I enjoy having good range, it's not a mile though.
On your 05, likely you need an additional box or something to bypass the factory security system.