I received one for x-mas. Haven't used it yet except playing on my trainer. Once the snow melts I was going to give a report. I weigh 150, so reliability is likely less of an issue. I think you have to make sure that all adjustments are tight. Also doubt that actually shifting on the fly would be all that easy or practical. I see it being useful on my TCR when I might vary from 74-76 degrees. Much faster and easier than changing seat posts and it's nice that no allen keys are necessary. Overall it seems like a very good product.