MP40 or 10's
 

I currently run one Vortech MP40 on my 120G reef along with some cheep power heads to achieve flow, i am looking at adding either another 40 on opposite end of tank or possible two 10's one opposite and one back wall. Just curious if any of you have any thoughts on the better setup or experience with them and what you would recommend. Thanks

i would do 2 mp 40 stagered on either side

I would also do the same two mp 40's

I have 2 MP40's on my little old 77 gallon, so my opinion would be 2 more MP40s for your 120 is almost a no brainer. For a while I considered getting an MP10 for the back glass since my 77 is a narrow tank, but the flexibility of the EcoTech drivers allows me to run the 40 on the back glass limited to a lower speed while still acting as a slave of the master, so it follows the selected mode, which in my case is Tidal Swell.

With my 180, I do 2 returns in the back corners facing inward, 2 mp40's with alternating reef crest in the back middle facing forward, and a wp40 wave from right to left.

Zero dead spots.

Edit: Should read that I have 3 MP40s, not 2.....