I'm not on a pump, but I have heard without exception, that they lead to better control of blood sugars. As for weight maintenance, I would assume that the ability to more accurately bolus for carbs and correct highs and prevent lows, all would prevent weight gain. (A couple ways: Less lows = less need to treat and risk of overtreating; Plus avoiding the cycle of more insulin to cover more food and needing more insulin, etc.) However, my thoughts are only theory. If you send me a PM I will give you the name of a website with a lot more diabetics and many of them on pumps. There is even a separate pumper's forum. I'm sure you will get some good input there.
One more thing I noticed re-reading your post: Are your Bolus doses fixed? That is definitely not the best way to match carbs to insulin, but an Insulin:Carb ratio leads to a lot more flexibility. If you haven't already read it, get Using Insulin by John Walsh.
And definitely check the thyroid
Thanks for that Zoelula. I was using Protophane prior to the Lantus and yes, my bsl's are better controlled now than what they were a few months back but the exercise has increased and the food has decreased but I will certainly discuss further with my endocrinologist at my next appointment.
Do you have any comments on the insulin pump ??
You don't say what you were using before Lantus. If the change has resulted in better control of your blood sugars, that could be why you are gaining weight. (Assuming, of course, you haven't increased food or decreased exercise). Unfortunately, some type 1's do develop insulin resistance after many years especially if during that time you ate carbs pretty freely and bolused for it. Insulin resistance leads to weight gain. You might talk to your doctor about possibly prescribing something for insulin resistance if he feels that is the problem.
You definitely need to check your thyroid, too, as thyroid disease is very common in type 1's. (unfortunately!)