I looked into them a couple of years ago when I was first looking into solar.
I thought that they were a bit goofy, but looked alright.
One of my friends bought one and tore into it after having some trouble with the inverter (iirc) and said that the insides were of less than ideal quality.
I would rather use a half size car battery and two or three 7 watt amorphous solar panels with a 75 watt inverter.
I also think that a 400 watt pure sine wave inverter is unnecessary with a 33ah battery.
A) at 400 watts you would only have around 20minutes of run time as you do not want to drain batteries below 50%
b) pure sine wave inverters are unnecessary for most electronics.
the only exception would be older microwaves, some tv's and electric motors.
basically only things that are classified as inductive loads, excluding light bulbs.
I guess it does have its place, however its purpose could be accomplished much cheaper.
"...Baler twine tie downs goin' down the road
On two bald tires and an oversize load..."