I remember a synthesiser project that, at one stage, took a second or so to settle, which sounded rather odd, but which was eventually managed. It used no IF. There was a very fast VCO and a very fast crystal, and one of those MOTOROLA CMOS synthesizers, a 74HC7293 (a long divider, not just a '293, much longer than a 4060) and a few other devices. Once supply bypass and other typical issues were managed, and the oscillators stoped appearing on the output, things worked OK. With long divisor chains, the response time is long. However, if you want only one output frequency and you can get within 1 Hz, you'll be pleased.

RE