Sqs vs SqsGen2 using RightScale right_aws GEM

Question

I'm trying to use the right_aws (1.10.0) GEM with Rails, and I've reduced my problem to a 3-line irb session. The following works

require 'rubygems'
require 'right_aws'
sqs = RightAws::Sqs.new("xxxxxxxxxxxxxxx", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")

while this fails

require 'rubygems'
require 'right_aws'
sqs = RightAws::SqsGen2.new("xxxxxxxxxxxxxxx", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")

with NameError: uninitialized constant RightAws::SqsGen2. I see the class definition in the GEM source, the documentation is old but seems accurate, but I can't figure out what I'm doing wrong.

And while you're at it, is there any reason if I'm building something new, I'd want to use the older interface?