I've been jumping back and forth between bupe and heroin for a couple of months now, and I cannot emphasize enough how tiring this gets to be after a while. It's a physical and emotional toll and just a heck of a lot of work that seems to not be worth the rewards. I think I've gone back and forth about 5 times since mid-summer, a lot of the time deciding on a daily basis when I'd be making the changes (mostly due to finances).
I used to know a dude who got pissed tested weekly for intense probation, and he would use dope M-R and subs F-Su. He did this every single week for the 6 months or so I knew him. I guess he would get used to it over time, but every week of having to take more dope the first day or two off of sub, and then time things right to avoid PW's, and then getting slammed with that "partial WD" (insomnia, lack of hunger, lack of motivation, depression, sweating, but nothing excessive like regular WD) that I've come to associate with bupe as a partial agonist...
I plan to party this weekend and then get back on sub on Monday and try and log at least a few weeks, if not months of sub maintenance. I think I might take just enough dope to be well on Sunday and then take sub Monday night. I'm flirting with sizable enough heroin binges that I still feel a bit of a rattle when I get back onto the sub, and I find that I need that controlled "just enough to get by" day of full agonist use before jumping on the sub. If I give myself that day, it is WAY less depressing those first few days back on suboxone.