This should be an interesting debate.
It's a whole lot easier to upgrade equipment than it is to upgrade an established tank so if it were me, I would put the money into a larger tank if you want one and have the room, understanding that larger tank means more or bigger equipment, of course. Then, assuming you don't have infinite money, I would buy good quality used equipment to start. Seriously, there is so much disillusionment and disappointment driven turnover in our hobby that the gently used second hand market is huge. Google your local reef clubs, Craig's List, or eBay. If you've been out for a few years and haven't been keeping up with trends you are bound to make mistakes in equipment choices. It's better to make those mistakes cheaply than expensively. After several months or a couple years you'll have a much better understanding of what you like and don't like, what works in your setup and what doesn't, and can upgrade over time.
Also consider that like everything, you get what you pay for but only to a point. There is a rapid increase in incremental improvement when you go from cheap to moderately priced and a rapid decrease in incremental improvement as you go from moderately expensive to really expensive. Take lights, for example. Some will recoil at my heresy, but are Radion Gen 4 Pros really that much better than Gen 3s at growing coral? Are they that much better than a moderately priced light or are you paying for name prestige that coral don't really care about? They're certainly a lot better than the cheap Chinese box lights growing coral in my tank but are they that much better than an LED/T5 Hybrid like this one for a whole lot less money?
https://www.bulkreefsupply.com/61-h...g-system-with-a360x-bracket-aquatic-life.html
For $523 you could get this and then add 4 AI Primes, XR15s, or Kessels second hand for less than half of what you would spend to light a Red Sea XXL tank with Radion Gen 4s. The coral will be just as happy. You can make similar arguments for pumps, skimmers, and all the rest.
As for your question about cycling and other trends, I highly, highly recommend the BRS/WTC Hybrid Tank series on BRS TV. Bulk Reef Supply and World Wide Corals teamed up for a very informative YouTube series intending to show a repeatable method for reef keeping that lays it all out for us. Do what they recommend and you will have a very high chance of success.
Looking forward to others' opinions on this. Should be an interesting debate.
