Filtration - no tank comes with adequate filtration! You can by an additional sump and its probably full of bioballs which are junk. Just like anything else in this hobby, you need to figure out what approach you want to take and adapt your setup to accomodate.
In my case I want SPS so need high flow and low nutrients. I've crammed 2 pumps for ~550 gph flow (10X turnover) in my left chamber, and will get an overkill skimmer for the right. I'm thinking the remora since it has an excellent reputation, but have also been told coralife makes a good skimmer I should think of. I like that the tunze will fit in the overflow and not hang off the back, but am not sure its enough for what I want. That said I'm sure its a really good skimmer.
I am just going to have rock rubble in whatever room I have left in the right section. A fuge with some chaeto (so no sand bed required) would be nice, but space is at a premium, I don't want to put on an extra light, and with this size tank whatever benefit the fuge gives me I can make up for with water changes.
I'm looking for my camera's cord so I can post pics... this weekend I hope!
Oh yeah, this is all just my opinion, and I'm sure lots of people have different ones... not trying to offend anyone but just putting my thoughts out there.