I think the one benefit iv suboxone has is the ability to dose multiple times a day (with low dosing) and get a nice little energy going and some euphoria. Another positive to iv suboxone is that if you want to use a full agonist, you don't have to wait twenty four hours to do it. If your dosing a mg and under total per day with suboxone(which is pretty much equivalent to taking 4mg sublingually) you can get high on your full agonist within twenty four hours, or at least that's what I found. Of course it depends what full agonist your using, but if your shooting your suboxone, than I'm guessing you probably would inject your doc too. I used to shoot my suboxone all the time, but quite frankly in the last year I've lost a lot of good veins due to cocaine, heroin, and shamefully, ambien and bupe+anti histamine combos. Injecting my suboxone just doesn't seem worth it anymore, as I also got pretty sick from using needles this fall, though that could have been avoided had I been more hygenic.
I also have to say that since the strips came out, I really don't mind taking suboxone sublingually. For me the pills were just horrible, so much that I would gag on them. Before the strips sublingual was not an option lol. Now However I've actually grown to Really like sublingual suboxone, and I find that if I stay at a low dosage(.5 mg in the am and pm)I still get euphoria just like when I used to inject the subs. I actually like the slow come one because I go from feeing kind of shitty, to feeling normal, and then I get kind of manic on it. Plus I don't have to worry about hiding my arms anymore, as I'm not shooting other drugs at the moment.