For my first race I felt a memento was very important - something to show I'd done it. I got a medal and I paid extra for a technical t-shirt.
Having now done about 20 races, I'm really not too bothered. The memento on offer is no longer a significant factor in deciding to enter a race (location, time, and good reviews are).
Personally, I'd much rather have a medal, t-shirt, mug, etc than a photo. I've got loads of photos of me running (most parkruns have a photographer) and I haven't felt the urge to print any of those.