Speaking to Snowman who has 2860-5's, he found just fitting cam gears made the biggest difference, so i'd at least look at those... the actual cams weren't that beneficial, if anything causing less down low, and hence took them out, but definitely left the adjustable cam gears fitted. The tuner really needs to know what they're doing though
Anyway, I ended up fitting Tomei 260/260 9.15mm lift cams + cam gears (no head mods required, all shims were fine).... gained 38kw@4 on the same boost, using 2860-5s... with more power throughout the midrange, but significantly more high in the rev range. Fine for my driving style, I don't need brilliant response as I don't do any competitive circuit work