Unfortunately, I wear both semi-formal and formal wear often; often enough to warrant having to have a nice tux and tailcoat. In fact, I probably wear my tails more than my tux. Yes, probably no one can tell the difference from the audience (I know I can barely tell the difference on other people when in the audience) but I can on myself. Also, a properly fitting/made tailcoat will be more comfortable to play in the one I have now, which is a very important factor. Well in that case, why not wait till BB has their next MTM/MTO event and get two jackets (tux and tails) and one set of trousers made in the same material so you can ensure a proper fit and save on not having to buy two whole suits?