Hello Chris,
The Viper is an incredibly reliable bit of kit. We have not had a motor go in two years, we have sold hundreds of machines.
At 400 grams per pole your arms won't ache, especially with the carbon head and tools.
5' working length is the perfect length for gutter cleaning.
Domestics gutters are usually about 16' high, which is three poles. Three stories is five poles plus a sixth if the ground drops away.
6' working length poles are a headache,two are to short for domestics and three are banging on the floor. When we used them we had to cut one in half to get a decent set of useful lengths.