My experience is that 14/47 or 15/50 (your 15/49 is real close) is an excellent street and highway ratio, with redline about 80mph.
Stock sprockets are good for about 74mph at redline. The engine will generally pull that speed downhill or when drafting a cage. 14/45 and 15/47 are good for about 84mph at redline, but the engine won't pull that speed unless drafting, downhill, and with a tailwind. Note the difference between "and" and "or".
With stock sprockets, 1st gear is almost useless on the street, and 2nd is too tall for any practical acceleration from stopped. With 14/45 and 15/47 sprocket sets, 1st gear is much more user friendly on the street.
On the highway, stock sprockets are buzzy, but don't necessarily limit top speed because the engine will barely pull redline, anyway, unless some mitigating circumstance allows. 15/47 runs into situations where the bike won't pull 5th, so a downshift is necessary to maintain speed.
The 14/47 and 15/50 sprockets seem to be the best compromise between having a practical 1st gear and highway comfort and performance for most people. However, there are specific circumstances where a higher or lower ratio would be better. If one's street riding is in a mountainous area, and one's highways are generally lower speed, 2-lane, winding, and steep, stock sprockets will probably give the best all-around performance. If one's street riding is in a mountainous area, and one's highways are generally higher speed, 4-lane, and steep enough to need 4th gear going up, 14/45 or 15/47 sprockets will probably give the best all-around performance since the downshift would be required, anyway, and a hill that requires a downshift to ride up generally is steep enough to allow a TW to wind up to redline going down. TWs are great fun at 80+mph.
Another place a 14/45 or 15/47 sprocket set works well is if one rides urban expressways on a regular basis. Several strings of vehicles moving in parallel lanes has a significant effect on wind resistance. Tdub would actually cruise along at 70-75mph quiet easily in fast-moving traffic, once getting over the rpm gap of shifting to 5th. She wouldn't run 65 uphill, but she would run 75. Go figure.