I've got this bag and have used it for about 50,000 miles of riding. I like it a lot. It's well made, and easy to quickly attach and detach with the velcro straps. My only complaint is it has faded to a dark grey from being in the sun so much on my trips. I recommend it.Just got this one in from WingStuff for $34. Haven't used it yet on my trip but seems heavy duty out of the box for the price.
This bag is what I have. It fits perfectly and it expands. It holds quite a bit of stuff too. I think they were just on sale for ~$79.00 at HLD (our sponsor). I'm not sure if they still are.Google: Nelson Rigg Goldwing GWS-500
I've used one for 3 years. Absolutely the best !
Even with the Utopia...fits like a glove.
If you want photos of mine and how the straps simply connect around the grab rails...just shout.