The 53ED was built on the infamous 15'10" hull that Hatteras produced for over 20 years. The boat was very similar to the popular Classic 53 and therefore it gets alot of crossover buyers. The 54MY and the 54ED were less popular but not necessarily any less desirable. The 54 has much more room than the 53 due to its wider beam. But, the 53 has the beautiful afromosia interior, while the 54's have lighter woods and laminates. I think it is a matter of personal preference. You will burn more fuel with the 54, but it is also a newer boat. The 53ED has the galley down, but the 54ED has galley up. Which do you prefer?
I love the afromosia interior and I would not want the light laminates, but that is my personal preference. If I was going to upsize from the 53ED, I would look at a 56MY or a 61MY, but not the 54. This is not because the 54 was not a well built boat, but because I like the classic Hatteras interior from the 1960's through mid 80's. I also prefer the nice curves of the the older Hatts to the "boxy" look of the 54 and other Hatts of that era.