For NYL the spread is the main thing. Refinancing that provides an equivalent spread does no harm. So the answer is--it all depends.
NYL has been very good about their dividend. That is the reason to buy it in the first palce. This is not to be bought for large capital gains.
Even if this goes up over 20 again, why sell? As long as you bought when the return was 10 to 11% per year, selling because you make a 25% return makes little sense if you are in it for income for the next several years. There is little sign that the dividend is going to be hammered and there is a good deal of insider buying which is almost always a good sign. There is no such thing as a guaranteed principle stability when you have income over 10% per year, but NYL for the past few years has a track record that suggests this is about as good as it gets in this type of high dividend buy.
I have bought a little more recently and wish I had bought a lot more back when it was in the low 16's. Then I was a strong buy--I am still a "buy" bordering on "strong buy". The income is so nice and I recently set it up as a drip.