No appliance to buy
It runs on an ordinary Windows 10 or 11 machine with 8 GB of memory, rather than a dedicated recorder or console.
UniFi Protect runs on Ubiquiti's own hardware and is designed around their cameras, which is tidy if you are all-in on that ecosystem. VISEC records on a Windows PC you already own and treats every brand the same.
It runs on an ordinary Windows 10 or 11 machine with 8 GB of memory, rather than a dedicated recorder or console.
Any ONVIF camera from any maker, in the same wall of views. You are not committed to one manufacturer's roadmap.
Part of the license rather than a separate product.
Often yes. UniFi Protect has a setting to publish an RTSP stream per camera; switch it on and VISEC can read that address. Check the option for your particular model first.
To drives you choose on your own PC, and VISEC can write across several drives as they fill.
No. One camera is free for life and more cameras are a one-time purchase.
The complete software, free for life on one camera license. No card, no email, no trial clock.