I'd be a lot happier with a 240 8x2x2 for life. or a 200 breeder at 4x4x2 (we have both) in fact we elected to to move pinky out of a 150 4 x 2 x 2.5 and into a 135 6 x 1.5 x 2 because of the added length.
Arowannas....RTC's and TSN's are ALL reported to go grow into monsters overnight.
WE have all three and while they DO grow fast. Especially at first...that growth tends to slow down a bit and falls WELL short of the reported 2.5 feet a year...
A lot of this growth is based on stories by people who had theses fish for a short time during the early growth spurts and then sold or returned to the LFS.
Unfortunatly the internets FULL of information of the...."I read about a guy who knew a guy who met this dude that told him..." variaty.