Biggest difference in a large vs. medium sized tank?

[viggen]

More water thus more salt to buy. If you add additives you will be using 3x's as much

In the past my regrets have always been not having enough room to setup my tank so I do not have to drag trashcans out into the house to do water changes (I do not have a filter room, always under the tank), then running the hoses through the house etc....... My present build (went from a 5ft long 260 to a 10ft long 475g) I want to have everything under the tank so I can simply turn a dial when I do water changes.

I always regret not going big enough......

Also I really like having a battery backup system on the tank to keep the water moving if the power shuts off.

 

[erics3000]

$$$$$$$$$$$$$$$$$$$$$ and $$$$$$$$$$$$$$$$$$$$ and lots more time and $$$$$$$$$$$$

 

[maroun.c]

Well as you say you're moving to a different tank category, While I'm all with going to the biggest upgrade in the same category (ie which don't necessitate an upgradein lighting, flow, skimming and supplementation) It is a bigger expense and a bigger hassle for water changes but then on the other side you'll have a huge tank which looks impressive and not the regular sized tank that anyone can have, not that some of the 75 G out there aren't 100 times better than my 75.
it will allow you to get more creative with your scape and allow you to fit in more corals and more fish which is always a good thing. In the end it's up to you if you can afford it or not but money put aside definitly go for it.
One additional advantage would be a lot more space under the tank to fit more things which makes it easier.