+/ 80-100 per sector in mind
Horizontal Pol. is selected because vertical polarization is used in many devices in the site, the horizontal is unused.
80 – 100, depending on actual customer daily usage but typically careful bandwidth limiting will be required, for example what I have done is to offer higher speed during normal daytime business hours 7am to 5pm (say 3Mbit) but during peak usage hours 5 to 10pm reduce it to 1Mbit, with ; http://wiki.mikrotik.com/wiki/Limit_Dif ... _and_Night
If there are many other devices on site then you will have to use AP's with good RF screening and placement is critical to reduce pick-up of other signals from these other devices on site, otherwise NV2 which will give more clients per AP and prevents hidden-node issues maybe effected by disconnects.