For me, they appear (but very, very rarely) when I am very dedicated over a prolonged time with that Religion.
So, they do not appear the same to me usually. Though I would not be surprised, that if I would dedicate the same focus and attention (and time) to a different Religion that these experiences will show similarities (not that they appear whenever I do things, I see it all as His Grace)
With Muhammad, my focus was more of study and contemplation, and it was the first time I was so dedicated with Islam over a prolonged time, and Muhammad appeared clearly as a person not as light
And it was of course all Grace, and I was glad it happened, because now I'm more open than before towards Islam, before I was open, because 1 of my Masters was all about Islam, but after such experience it's more natural for me to believe Muhammad is for real (even now, as I see they are beyond time)
The experience with Jesus was in a setting with a group of ca. 200 people all chanting hymns (Portuguese), and really beautiful, and full of 'light', and I was in a joyful mood too, hence the appearance maybe came more as light, but that is just my guess.
And prior to this event, as a preparation, I kept very strict vegan diet, and lots of fasting as well as Silence and Solitude (far away from all "sex, drugs and rock' n roll"), not talking to people for ca. 2 weeks, and also silence during the 12h ceremony; I was really in 1 of my extreme enthusiastic, fanatic moods back then (nowadays I'm a bit more 'lazy', still a good focus, but less extreme).
All this I did not do when Muhammad appeared. So, I don't compare both myself. Both were very useful to me, and I really appreciate these gifts.
I am a person who likes to be in control and know things and be certain about things, but when it comes to Spirituality nothing is fixed, IMO, it's all reflection of my own action (of course all His Grace), and I'm not in control nor do I understand it, so I just accept what happens and continue