The Stroboframe Pro-RL was my choice. Since I often shoot from a seated position, I find it useful to be able to get the flash really high. As well, I've found it has sufficient adjustability to be used with the MZ-5n (with battery grip), the MZ-S (with battery grip), and even the 6x7.
Also, as a former mechanic and millwright, I can appreciate the quality design, construction, and machining of the unit. It's a pleasure to use, and you can change the flash height and angle almost instantly. It's a bit bulky, but it works well and really looks the business (sometimes that matters). Pat White
