Macro Lens Question

[Overread]

At the moment I typically use a 1.4TC on both my macro lenses (the 150mm and 70mm) since image quality is only marginally affected and yet it gives me not only a slightly longe working distance at 1:1 magnification, but also a little more magnifaction for getting really close to smaller insects and to get section shots of bigger ones (mostly the head)

Added to that I have started to also carry around a Raynox DCR250 for some much closer shots. I use this far less since its very demanding to work with, but its good when one has a sleepy insect. I prefer to use it on a tripod, though handheld is possible, (though you do need to brace yourself, freestanding is a no, but crouched on the ground or leaning on a wall works).

The 2*TC I use less since it gives noticable softness (though the DCR also does this) and to be honest I haven't looked at using it in a while, I probably should at some point.
My Extension tubes see even less use, though its again something that I do want to look into - I tend to avoid them as it fixes me for macro only - the Raynox I can unclip in a flash to get back infinity - tubes take longer to remove.