I know that you asked for bib tights. (which makes me smarter than at least one guy) I don't have any experience with bibs and frankly don't see the need for them. I do have some experience with tights. I have tried a number of different winter models including the Performance Winter Tights.
I was never quite happy with anything i tried. Then i read about this site
The company is called Foxwear and it really isn't much of a company at all. In fact it is basically just one guy and his name is Lou. If you call, that is who you will talk to. He will take your order, make the product and also ship it. LOL.
Seriously, I was a bit skeptical until I visited with Lou for awhile. He is very knowledgeable about cold weather sports and different fabrics. That is what makes him unique. He actually tries the stuff he makes and then improves on it. I called him a couple years back and asked about tights. He proceeded to give me a bunch of good info and then sent me about 15 different fabric samples in the mail.
After i got the samples, i then called him and we came up with a custom plan for my tights. I selected midweight windshield to make my pants based on his advice. Through our conversation, it was also decided that he would make them extra long for me and that he would make the waist so it would rise up to just below the breast bone while seated on the bike. This was a need for me because i was tired of getting the "red stomach" from the wind.
Well, he made the tights and sent them quickly. Interestingly, he sent the tights with a bill. I hadn't even paid him yet. It was all on the honor system. You don't see a lot of that anymore. Anyway, the tights turned out just perfectly. They are so comfortable and solved all of my problems. The windshield is just thick enough that my tights almost start to resemble tight fitting pants. Oddly, this is something that i also consider at attribute, because they almost look "good" enough to wear into a store or something if you had to.
Please note that I have absolutely ZERO interest in Foxwear. I am only reporting a very favorable unique experience that i had with a vendor. Anyone that knows me would also know that i would be reporting a very unfavorable experience here as well, if warranted.
I just think that it is very cool to get a pair of custom made (based on your measurements) tights in this day and age for very little money. When was the last time you were measured and somebody made a piece of clothing specifically for your body?