I for example use a 8(10) port d-link dgs-1210-08p with passive cooling.
This one is having POe on all 8 ports, but...
DGS-1210-08P (802.3af/8 ports/45W)
So total max is 45 watts. And 802.3af is max 15.4 watts per port.
Using for:
Hikvision Ds-2cd2542fwd (max 5 watt)
Hikvision DS-2CD2332-I (max 7.5 watt)
Hikvision DS-2CD2432F-I(W) (5 watt max)
802.3at would have been nicer, but no passive cooling and using more power to operate (this one 5.6 watts without POE active) and will have most likely fan for cooling.
So for my setup this seemed the best option (100€ new price here at the moment i bought it)
For larger setup with more cameras i would have gone for larger number of ports and 802.3at support.
POE is great option to have, only one cable, and that is for difficult positions less a worry than 2 cables to pull.
And indeed, a ptz can have issues, i mispatched my 5220 and it seemed to work until the ir came on, than it simply reboots..
I have the 5220 on ultra POE injector (60 watt) as it is in the specifications for 31.5 watts.
That "ultra" is defined as:
Power over Ethernet
PoE Standard Ultra PoE over 4-pairs UTP,
IEEE 802.3at High Power over Ethernet End-Span / Mid-Span PSE
PoE Power Supply Type End-Span + Mid-Span
Power Pin Assignment
Pair 1 End-Span: 1/2(+), 3/6(-)
Pair 2 Mid-Span: 4/5(+), 7/8(-)
PoE Power Output
DC 50V / 60-watt PoE via 4-pairs
DC 50V / 30-watt PoE via 2-pairs
It is a Planet POE-173 60-Watt Ultra Power over Ethernet Injector
http://www.newegg.com/Product/Product.aspx?Item=9SIA29J1976933