Efficiency or power?

[Benjidubwise]

So I'm looking at picking up another light for an extra little space I have.
The space is 70cm x 70cm or just over 5 square feet.
I'm comparing 2 models from UK company 'Invisible Sun'. They are a similar price. One is more powerful but slightly less efficient where as the other is less powerful but more efficient.

What's the one to go with here?

The first is 240 watts from the wall & uses (less efficient) SAMSUSNG LM281B + LH351H v3 660nm with an efficiency rating of 2.5 umol/J.

The second is 150 watts from the wall & used (more efficient) SAMSUNG LM301H Evo LED + LH351H V3 660nm Deep red. with an efficiency rating of 3 umol/J.

 

[Zardgreaux]

240 watts X 2.5 umol/Watt = 600 umol of light.
150 watts X 3.0 umol/Watt = 450 umol of light.

If you are looking to maximize light, go with the 240 watt fixture. 2.5 is still plenty efficient and you are getting 33% more photons from it overall.

 

[Bob's Auto's]

For that surface you don't need more then the 240Watt, but you can grow more then sufficient with 150W as well you know...
I'd go for quality over power.