Hi mukesh,
Ya i have used the gem, quite helpful and simple if your load is minimum and if your main server can handle the extra load.
Pros:
The thing i liked about sucker punch is its simplicity of integration, and didn't cause much problem for me.
Cons:
When the email count reached 10,000 emails per day itself, the main rails app started to take the toll. Our server was an ec2 micro.
Finally i moved back to sidekiq, as i was able to run the worker on another server (another ec2-micro).
My verdict is:
Sucker Punch is good to get started, really simple, light and clean. But once the load increases you should consider moving back to sidekiq.
PS: Regarding the queue not purging i had the same problem. I wrote a rake task to run these three commands
Sidekiq::Queue.new("infinity").clear
Sidekiq::RetrySet.new.clear
and add it to my capistrano deploy file.
cheers,
ᐧ