The extra outlets are a plus over the 550 as well.

The outlets seem to be built better than the old model, all the plugs fit snugly whereas the older model has issues with plugs easily falling out

The outlets on the surge protector side do not work unless you use the software to do a self-test

Ample outlets, but not all of them are battery backed up.

The new one is working well, has more than adequate back-up capacity, as well as two more outlets than the old unit.

Well spaced outlets, no transformer hum, clearly marked, good price. wish it was a wave conversion type

I love the smaller footprint and the 10 outlets.

Having 10 outlets is great too

One of the features I like is the 10 outlets

Love the extra outlets.

A few outlets don't work.

I've seen several complaints about too few UPS backed up outlets on the device.

I really like the extra outlets,worth the cost

This is one of the best values and more than enough power/outlets for average to mid-level use.

I would like a couple more outlets on the backup power but the bigger unit is a little too pricey for me

Also like the Master outlet feature although it's not used in the office where my computers are always on.

So this is a bit of overkill with five protected outlets.