The question of IP versus analog has been posed now for about five years.
More than five years ago there was a large group of early adopters who had specific reasons or deep enough pockets to "go IP."
Today, IP video camera and storage costs are at an all-time low. Manufacturers have been making the sometimes drastic migration to IP. Several manufacturers have even gone so far as to discontinue analog entirely. Other full-line manufacturers continue to support both technologies with enthusiasm.
So, now for your project: IP or analog? There are a lot of considerations. Let's address just a few big considerations first:
Do you want a high resolution image on the screen or are you just interested that "something" out of the normal is occuring? If you are just "observing" a scene, then standard resolution will work for you. If you need very fine detail, you've answered your question already....it's time for IP.
Do you have an integrator or onsite staff that can support an IP video solution? There was a time when each camera had a dedicated cable coming back to a "head-end" recorder. Once the system was installed it essentially ran "forever" without much support needed other than camera cleaning and verification that recording was occurring., These systems were and continue to be "rock solid." If you're integrator is IT0savvy or you have an onsite IT team that is going to manage the IP video solution for you, then IP is a viable solution.
Do you have a desire for many people to have access to many cameras from many locations? If so, then IP provides a variety of connection methods. These systems also come with the ability to utilize apps, web browsing, decoded monitor stations, and operator client interfaces to access live and recorded video. The more people you have with a desire to see video from a variety of locations, the greater the odds that IP video is the right solution for you.
Do you have a need to record video for an extended period, perhaps more than 6 months or for several years? The longer you need to store video the more likely you will need an IP solution. NAS or iSCSI can provide uniquely large storage capacity unlike a standard DVR which is usually limited to several terabytes. Long term storage = lots of data to be stored.
It used to be that a small system would only require an analog deployment and a large system would be considered for IP. Today you can get the same horsepower out of your system from a small all-in-one network appliance like available in the IONODES hardware platform or the Bosch Divar IP 3000 platform. Big systems generally use the same applications,just on much larger hardware platforms using a few servers and iSCSI storage appliances from manufacturers like NetApp, SuperMicro, and others.
This only scratches the suface. What you need is a trusted resource to help you decide. An adviser without an IP or analog agenda is preferable if you can still find one.