Thanks for the feedback Jeff...
I'm not too concerned about the looks and after some measuring I don't think the smallest ones stick out too much.
After reading a little user review I came across, the chap said they were great for what they are but the only 'criticism' as such was that the suppied bolts didn't fit quite well:
"I upended my speakers (XTZ 99.36 Floorstanders) with the intention of removing the threaded feet and simply using the existing threaded inserts to attach the outriggers, unfortunately life is rarely that simple. The bolts that come with the Soundocity outriggers, whilst the same diameter, are a different thread density, being somewhat coarser than the ones employed by XTZ. As I didn’t have any other bolts the same size I decided somewhat cautiously to remove the XTZ threaded inserts the replace them with those supplied by Soundocity. Despite me owning the only 50 piece Allen-key set which doesn’t seem to fit anything I have ever bought, I eventually manged to replace the inserts and still maintain a firm base for the outriggers. I was especially careful not to overtighten the inserts as I was pushing my luck re-threading these into MDF."
I'd rather not have to go through any hassel to try and fit these things - I don't suppose you might have any practical experience if the bolts fit into the metal plate?
ta
Dave