Yes, a turbo beanie isnt an area I would be trying to save a few dollars. Far too easy for it to all end in tears.
Stick to reputable brands like Garrett et al, and you should be right, but as has been mentioned, it comes down to how well maintained the rest of the turbo is, so make sure you have oil lines that dont leak, and check it periodically to ensure it isnt being slowly soaked in oil.
If you use your car for track work, then I would suggest that it would have more positives than negatives, but for a strictly street car, I think I would tend to go for a well made, formable heat shield, with a good air gap, to stop radiant heat melting wires and hoses in the vicinity.
I have a T4 beanie sitting in my office that will be getting fitted once I get my FFIM installed so will report back here if I find my turbo now spools from idle