Before I can give you my thoughts on this a little backstory on my series Bright Morn of Issareth (you'll understand my answer better)
It's a fantasy story where the people of his race live to 200 years, die and are reborn as half human but think they're all human until puberty, when the other genes come into play. When they reach their 30th year they spend the first month of it in a semi-comatose state reliving their memories of the last year. They also experience (reliving, not just observing or thinking about) memories from other years. As they age the memories happen frequently, by the time they reach 50 they know all their past lives.
I tend to plunge my character into his memories with little warning. Sometimes I do say he's stepping into one but most of the time not. I haven't had any complaints and if anything, I've had requests for stories to flesh out more of the memories. I've been told by those liking this that it really shows them (not tells them) what the characters motivations are and connects them to his emotions.
I am a big advocate of doing what you think is best for your story. What hit me about the comment above was "a few people." How many billions of people are there in this world and how many hundreds, if not thousands might read your work? Are you going to let your creative process be dictated to by "a few people?"
There are also a few (or a lot) who have no problem with dream sequences or memories, if anything, they like them.
You say that both ways of approaching this work, and read well. Which one do you like the best? Which one do you think serves your character and story the best? Do you want people to go on the trip with your character or just watch the video while someone else narrates it?
The thing about the dream sequence is that the reader experiences and feels what has happened, otherwise they're getting the information second hand which is a huge degree of separation and with that goes the visceral "experience" for the reader.