I would say.... that depends. If you disarmed the system right away (or during the time when the panel was still online with the station), then they could have received a "cancel code" along with the alarm, and most stations won't even call, since they know someone with a valid code has disarmed the system. Your station might simply have been doing a double check (as many do) as a matter of policy, which can be some minutes afterwards depending upon how many alarms they are receiving at the moment without cancel codes.
The normal interval to respond to an alarm (assuming no receipt of a cancel code) I expect should be immediately or within a minute, depending upon how busy they are at that moment. Early morning and around 5 pm seem to be the busiest periods of a workday when stations are running at peak capacity, which would normally slow things down a bit (Lots of people disarming their panels at work and screwing things up etc.....)
With a cancel code, response can vary (assuming the station calls at all) and can vary greatly based on other alarms being received at the same time. They should probably be explaining to the end user they are just doing a double check ; otherwise, the impression left is slow response as you felt. Cancel codes are one of the things that dramatically decrease problems for customers; however, they certainly can leave the impression of poor response.
It should be noted however, that a lot of companies (and customers) prefer NOT to use cancel codes and wish the station to call on every alarm trip. This is a simple programming change in the alarm panel. While lack of a cancel code increases the workload on the station (and IMO likely doesn't add much benefit to the end user), it certainly does increase the false alarm rate substantially.
If I lived in LA or another large community with lots of crimes against people, I might be tempted to forget about cancel codes (and probably also activate a duress code in my panel ). But if I lived in a normal community where crimes against people was not a major issue, a cancel code is much more likely to prevent a false dispatch and a fine than it is to decrease the effectiveness of your alarm in any meaningful way.
This is something you should discuss with your alarm company in regards to your personal situation.
R.H.Campbell Home Security Metal Products Ottawa, Ontario, Canada