Glad I can help:)
Most cats tolerate insulin injections quite well so I'm glad to hear that Woody is one of those patients.
It sounds as if his blood sugar values are likely reducing but without a glucose curve, we can't really know how quickly the insulin is working in his body, for how long it's working and how low the insulin is taking his blood sugar.
I've found that managing diabetes in cats can sometimes be a challenge but I would expect him to start acting more like his old self after at least a week or so.
The following link discusses at-home testing for diabetic cats which actually isn't quite as daunting as it might first appear. Taking blood from an ear vein and using a glucometer at home is vastly superior to hospitalizing a cat since stress can so dramatically affect their blood glucose numbers.
At this point, we don't know if he's a hard to regulate diabetic or not but the following link also discusses this particular situation:
In fact, if you look to the right hand side of the page of any one of these links, there's a number of other articles which discusses diabetes in great detail. I suspect you've already done a large amount of homework on the subject but if you haven't, then they may be useful.
Here's another great link as well: http://www.vet.cornell.edu/fhc/health_information/brochure_diabetes.cfm