While very out of control diabetes can and does raise lipid levels, most type 1 diabetics have better cholesterol levels than nondiabetics. This sometimes surprises people who do studies on the topic.
For example, in this study, 44 overweight kids with type 1 diabetes were matched to similarly overweight kids without diabetes, who were the same age, etc. The diabetics had lower total cholesterol, higher HDL (the one you want) and lower LDL and VLDL.
The authors speculate that this is because, if diabetes is what's making you fat, it doesn't raise your cholesterol, vs. if a sedentary lifestyle is making you fat, it'll also raise your cholesterol. I don't know. Personally, I don't think that explains it. In any case, it's also interesting to note that overweight kids with type 1 diabetes have blood markers that suggest better health than nondiabetic overweight kids.
This study similarly surprised its authors, and is about the same thing.
While a number of studies have convincingly shown that diabetes can have bad affects on your ability to think, in a number of studies diabetic children acheive better grades and higher standardized test scores than their non-diabetic peers. This is especially apparent in math- it's good practice, I guess.
And, of course, diabetes is a risk factor for climbing Mt. Everest!
(since I wrote that piece, a young woman with type 1 diabetes has climbed on Everest as far as the base camp, and another group of four young people with type 1 diabetes are planning an Everest climb as part of an advertising campaign for a diabetes company).