To get off the topic of Wallins....
I lived in Monterey for the past two years and during that time I patronized the following shops (in alphabetical order):
Any Water Sports
Aquarius (Del Monte)
Aquarius II (Breakwater)
Bamboo Reef
The Gas Station (Corner of David and Lighthouse)
Monterey Bay Dive Center
In recommending shops I would put AWS number one. Within Monterey, I would recommend Bamboo Reef.
To be fair to Aquarius II I did not use them often because they do not carry nitrox. The few times that I delt with the shop were for quick air fills which met my expectations.
During my first year in Monterey, my primary dive shop was Aquarius. I enjoyed the ample parking and quick regulator service (within a week). However, the gas fills were less then optimal (hot fills, but they were quick and they banked 36%) and the merchandise did not generally fit my needs. I did purchase a regulator set and two high pressure tanks (~$1500). Unfortunately, about a year into my time in Monterey the new owner (Bruce) and I had a falling out. During the period of April-June 2007 I participated in and helped coordinate logistics for four technical courses run in Monterey. Aquarius was unable to handle the filling of multiple doubles and stages in an timely and accurate manner (see the Great Helium Dump of 2007 for more details). This was due (IMO) to new employees who did not know what they were doing along with poor fill station procedures. Furthermore, accounting was inflexible with us unable to run tabs and settle bills at the end of the class. As a result we were told that we were unwelcome in the store since all we do is get fills and all our tanks are a pain in the a$$ to fill.
After that, I began using Bamboo Reef and they have served me well for the past year. The fills do tend to be light (1-200psi short of service pressure) but this has not bothered me. I would like the staff to "not sweat the small stuff" as much for example, topping a tank off without charging for a full fill.
I have no strong opinions with regard to MBDC. I have done minor dealings with them and have had no problems. Overall, they were not really suited for my needs.
The gas station was extremely difficult to work with. I needed to provide my own connections to connect to the fill station ($30) and I was only able to get 100psi in my tanks.
I have been to AWS a half dozen times in the past two years. They have always carried the equipment that I needed (regulators, 40cuft bottles, etc.) and have given me a discount when I purchased them. (no asking on my part) Recently, I sheared the first stage off of my doubles (din adaptor broken and needed to be replaced) and Frank fixed it for me in less then 10 minutes, no charge. Service on two regulators took less then a week. Every fill that I have gotten there was accurate and over the service pressure of the tank. The best thing about AWS is that they don't sweat the small stuff.
Jonathan
P.S. Anybody know a good dive shop in the D.C. Area?