this is the deal w/ TBS rock. I love it. You have to like a 'natural' looking tank though, as the rock you will get will have very little die off and will have lots of macro algae, sponges, HHs, bad HHs, etc. for a long time.
The rock, if you buy the 'package' works out to about $5 or less a pound- not bad since that includes all the cleanup crew and sand and 'extras' they throw in! You do have to pick up at laguardia airport though- since they ship in water its lot of weight and the cheapest method of shipping is air freight.
Total time from harvest to pickup at laguardia for me- less than 8 hours!
Bad stuff- w/ that large of a tank you WILL get bad hitch hikers!!!! No doubt on this, unless you rinse in fresh water or something (which will kill off all sponges, cause your tank to cycle more, etc.) or can quarantine your rock for a while to see what you have on it. 10 months later I am still finding new hitch hikers! I happen to love natural looking tanks, but I do hate the mantis that is killing my nice fish that I get! He will be hard enough to get out of my 16g, having multiple mantis' in a 120+ gallon will be a real :banghead:!!!
The rock is more dense than fiji, but much much less dense than tonga...I really have no problem when it comes to this, plenty of caves, etc for me!
Bottom line- don't get this for 100% of your LR if you don't plan on spending a long time getting bad pests out. If you want a natural looking tank, get some - catch the bad HHs, then use it to seed the rest of that tank.
This rock would be perfect as its own little biotope though- I have lots of random corals even that are still growing on it. I have no macro algae 'problems' now that I've been trimming it and as my 'pods population has gotten large they are keeping down algae problems- but if I didnt' make a big effort in the beginning to keep the macro from overrunning the tank, I would still have a ton of it today!
Lots to think about w/ this kind of rock- I will use my current rock and sand in all my future tanks- to seed them w/ the micro life I love to see in a tank...if you are just into the looks of the coral and coraline covered rocks then just get cured Fiji and save yourself a ton of trouble.
Ask me any questions you want about TBS rock! (well I will not be around so much the next 10days- I'm on vacation- so I might be a little delayed in a response!)