You have a lot of really good responses here. I cannot add more but, I can give you my experience.
I have 2 tanks:
75 gallon set up at my office using T5's, wet/dry filter, protein skimmer
125 gallon at home with MH lighting, refugium and no protein skimmer (risky but, I rely on macro algea)

In the 75 gallon with T5's I keep anemones, SPS. LPS, and softies. The same with the 125.
Here are the differences and you will see I prefer the 75 with T5's and wet/dry filtration.
The 75 gallon temp stays stable, the 125 flucuates 10-15 degrees a day with the MH lights going on and off.
The 75 looses 4 cups water a day, the 125 takes 2 gallons to top off a day. If you don't have a RO/DI system, you will want one with MH lighting. Also, glass tops go a LONG way to reduce evaporation, if you don't have one, get one!
The 75 is QUIET!!!! with the wet dry, water flows into it on the filter floss before entering the filter, NO SPLASHING!! In the 125, it sounds like a waterfall in my living room.
I clean the wet/dry filter floss with the used salt water from my water changes monthly when I do water changes and the bio-balls every 4-6 months... no nitrite problems.
I use a protein skimmer on my 75 gallon but, after 5-6 months it rarely needs cleaning as the skimate is minimal. Increased skimate makes me look for a dead fish, coral, or food build-up. No feed-back on the refugium without a skimmer.
I definately favor the 75 gallon and am seriously considering tearing down the 125 and re-doing it like my 75 gallon.
Others will have other opinions and every post you have received is a GOOD one. Good questions and good answers.