Looking at reactors for my upcoming 150 build. I have been looking at the two little fishes 550 reactor and the Nextreef reactors. this will be under the cabinet and possibly in the sump. I know the 550 is rated for tanks up to 600g but I'd rather have one that is too large than have one that just barely does the job.

I'm sure they all have their pros and cons so I'd like to know which ones you guys like and why.