The three of us seem to be at different stages of the same situation. I would hate to wish it on anyone, but it's soooo nice to know this. Sometimes I feel there's no one left in my world who 'gets it' - it's very isolating, isn't it ?
In answer to your question pepperminty, basically HRT 'tops you up' but the pill controls/takes over. As a result, those of us with severe fluctuations have found HRT, whilst better than nothing, still results in poor symptom control. Some ladies have taken stronger HRT - usually 200 mcg patches, to suppress ovulation, whilst others have opted for the pill.
Hrt is more likely to be bio identical, with most pills 1 or 2 mg; the pill is rarely bio identical and usually 3 mg or higher. The main exception is Qlaira which averages 2 mg only and is bio identical. Qlaira has been super for me for over seven months, but recently I have suffered with headaches and low moods, plus increased itching (had this on it initially). 
Hope this helps x