As someone who rarely needs Photoshop, I've done all my work on demos, and it's been fine. Adobe changes versions often enough that I just download the fresh one next time I need more work doing. They also have Photoshop Elements, which has much the same features, but being an entirely different demo, gets me another 30 days.We discussed it at length in the thread on Tested. The TLDR is that we bought a legit copy to use for benchmarking, but activation prevents. Because it has to be moved from machine to machine as we test new machines, eventually normal copies stop activating properly. Adobe limits the number of times you can make that transfer, and there's also a fairly real chance that we'll fuck up and leave our real copy activated when we send a machine back make it too high risk to use a legit copy. We tried using demos at Maximum PC when Adobe changed the activation policy (Adobe used to provide copies with 50 activations for benchmarking purposes), but for some reason that I don't remember, Gordon said the demo was unreliable. Hence, torrents. FWIW, the license that we use for benchmarking has never been used for actual work. It's purely a benchmarking tool.
TLDR for the TLDR: activation is a hassle for benchmarking
It's not an ideal solution, but it's better than piracy.