I don't notice a stim effect on var. The biggest thing I notice is that I sweat a lot more lol
DHT has an affect on the nervous system. It increases neural efficiency which increases strenght, recovery, etc. Other stuff also has an effect on cns. Stuff like amphetamines, modafinil, etc. But I wouldn't necessarily put dht in the same basket, especially when it comes down to it's effects.
I think if one has low dht he might notice an effect when taking aas. You know a lot of side effects from low T like depression, foggynes - adhd like symptoms, sleppines, low libido, etc. are from the lack of DHT not T per-se. So yeah, DHT plays a big role in the body but I doubt you would notice much stimulant effects, maybe as I said, if you have low DHT to begin with. But also in that situation, I can tell you from my experience (as I have on the bottom end of lab range naturally DHT), I don't notice much stimulant like effects. Stimulant in the sense off caffeine for example. I do have better focus, drive,... but also more agression which leads to less psychological stability. Most of, if not all, mental sides when taking aas come from DHT. Also strenght, which is not an expression of more newly acquired muscle tissue, is from DHT.
You can easily find this out for your self by taking 50 to 150mg's of proviron. That wont have any muscle building effects by itself, but it will show you how much dht gives - you personally - in terms of mental effects. Proviron is basically synthetic DHT. DHT aas like anavar are chemically altered and may or may not give the same benefits as pure DHT. Also you can take epiandro. That's a prohormone to DHT, which means it converts to DHT in the body when consumed.