I bought a Multiblades vise for the Festool MFT/3.
This vise clamps on to the Festool MFT/3 quickly and firmly. I have used it for sawing and planing and, in this case, for drilling dowels into a beveled piece that would be hard to stand on the MFT/3 surface. I like being able to reposition it quickly. I also like the fact that it is rock-solid in its attachment to the MFT/3.
Of course, you can clamp a workpiece directly to the side of the MFT/3, as seen in the following picture. Since I purchased the Multiblades vise, I find myself using it in preference to the side clamping shown below for small and medium pieces. For large pieces Multiblades supplies deadman hardware with the vise, but I have not used that.
I saw very few mentions of the Multiblades vise online before I bought it, so I thought it would be nice to share my very complete satisfaction with it. I'm in no way affiliated with Multiblades or anyone else for that matter. There are a kadillion websites about the MFT/3 itself so I won't say anything about that here.