Hair dyes type - for real?

It depends on lots of things. Firstly the individual dye, each brand has certain colours that are more strongly pigmented, so comparing say MP Hot hot Pink (one of their best shades) with something like Directions Lavender (not very strongly pigmented at all) is not a fair comparison. Each brand has some great colours and some that are not so good in terms of coverage/longevity, so you can't use a blanket statement about which brand is best.
Then there is the base. it is not just the colour, but also the porosity that affects how well a dye takes.That is why you can put the same dye on two people with bases that  look identical, but still get different results.
Then there are all the other factors, how well did they apply it, how did they prep their base, how long did they leave it on, how do they wash it, etc etc So many factors affect longevity. often people complain that a certain dye 'didn't stick' to their hair, but they were washing daily with sulphate shampoo and hot water for example.
Different brands definitely suit different people, but with the right base and the right haircare routine any well pigmented dye should work. They are all basically the same in terms of ingredients.

Yeah, there's a whole host of variables that make people prefer one brand to another. Cognitive bias ends up playing a part. I know I'm a little biased against manic panic as there's been a few colours I've not had a great experience with. If I'm really honest with myself, there are manic panic colours I have liked and lasted fairly well, but I still generally don't use it unless it's a time when I want it to fade fast... I also then take measures to make sure it doesn't last long, so it's probably no different to if I used another brand.

There are a few that most definitely last longer than others though. Special effects nuclear red, napalm, virgin rose and atomic pink, directions turquoise etc etc. That's usually because they're very heavily pigmented.

Yes, I waskind of expecting that  😀 I always say it depends what they are expecting from the dye.
Thank you!

I agree with Janineb about cognitive bias, for instance I only seem to get a couple of washes out of Adore dyes but because they make my hair look smooth and shiny I tend to think of them as better than Directions which last a little longer but can tend to look dull or dry on my hair.

I tend to think of Nuclear Red by SFX as a completely different type of dye as it is so much more highly pigmented, I loved it when I used it but there was no getting it to fade so I tend to only recommend it to people who are ready to commit to a bright shade for a long time or who are happy to go darker afterwards. If someone likes to change up their colour a lot I would probably actually recommend directions despite my own bias as it does seem to fade out quite well. I find people's different experiences with the different dyes really interesting.

Directions really varies according to shade, you won't easily fade Plum, Turquoise or atlantic blue for example, they really stain. Lagoon Blue, Lavender, hardly last beyond one wash. You just can't generalise about a brand