Weirdly and oddly...but then again, DH and I are weird and odd people.
We have not been doing it as much as we both wanted to. I have had terrible m/s, and in fact, the longest I've gone between actual upchucks has been 12 days (last week), and I'm at 22 weeks now. So for about the past 20 weeks, anything that felt even remotely up and down made me seasick! :Puke So we'd try for once every ten days or so for sympathy, and to give each of us a little relief (poor DH did some serious work!).
But with DS, my second trimester wasn't that hormonally beneficial - with him, my m/s cleared right up so we could get back into the swing of things, but it wasn't special.
Oddly enough, earlier in 2004 when I miscarried, I discovered that I have a bit of a b-vitamin deficiency--B supplements get me revved up (and DS also started weaning). But this past summer I discovered a randier me and hubby and I both loved it. Which resulted in this pregnancy.
Now that the hurling isn't so frequent (up to 3 times a day for a few weeks on end), and the nausea is subsiding, and the acid reflux seems to be getting down into a manageable level, all we have to really deal with now is, like an OP mentioned, regularity, and the fact that Twoey is a low rider, and sits right on the topside of my cervix, which makes things veddy uncomfortable unless we switch positions a lot. Which I don't mind, but it really makes you have to be flexible in getting into a groove.