There is no need wasting money on an office curve if you are home testing. Office testing is expensive and unreliable, since most cats have inflated blood glucose values at the vets office due to stress. This leads to inaccurate and dangerous overdosing.
I hate to say this, but most likely the Hills R/D caused your cat's diabetes, and the W/D is just as bad. I'm pretty sure dry W/D is what caused Bandit's diabetes. Unfortunately, your vet is not up to date with current feline diabetes treatment guidelines. This is very common as treatment has changed drastically over the past few years. Please print this document and give it to your vet:
http://www.aahanet.org/PublicDocuments/AAHADiabetesGuidelines.pdf. Note p. 217-218, where a low carb canned diet and home monitoring are strongly recommended for treatment.
The only prescription diet that is suitable for a diabetic cat is canned Purina DM, but it's pretty much the same thing as low carb, cheaper grocery store foods like Friskie's, Fancy Feast, or Special Kitty so you're only paying for the label.
The good news is that with Lantus, your cat has an 84% chance of remission IF you are feeding solely a low carb, canned diet, and making insulin adjustments via daily home testing. I've attached an article on this for you to print out and give to your vet as well.
If you give this information to your vet and they are still insisting that you don't need to home test or change the diet, I would change vets.
Bandit ate dry Purina indoor for the first 6 years of his life, and he became morbidly obese off of the dry food. His ideal weight is 13 lbs, and he weighed 23. I took him to what I thought was an expert in feline nutrition, one of the inventors of Hills Science Diet. He put Bandit on dry W/D, then Science diet light. Bandit lost the weight, but developed triaditis from the food. I then switched him to Iams weight control dry. He started to gain weight again despite restricted feedings. Finally, I did some reading myself on feline nutrition and was shocked at what I found. I immediately started feeding a half canned, half grain-free dry diet, but it was too late. Bandit was diagnosed with diabetes a few months later because of all the excessive carbohydrates I was feeding him. My other cat was diagnosed with kidney disease at the same time, again, from eating a dry diet her whole 14 years.
However, this is very important, do not change the diet before home testing. Getting rid of the dry can cause some cats to immediately go into remission or reduce their insulin needs, so if you're not testing and still giving insulin a dangerous hypoglycemic incident can occur.
Here is some more information about the health problems caused dry vs. wet food, written by a vet who is an expert in feline nutrition:
www.catinfo.org
Dry food and Obesity:
http://catinfo.org/?link=felineobesity
Prescription diets:
http://catinfo.org/#Prescription_Diets_and_Marketing_Labels
Diet and diabetes:
http://catinfo.org/#Diabetes