I used to be totally against SEO's, BUT that was because the first thing that came to mind was Valentino and his "napoleon Complex" yada, yada, yada.....Then after reading up on what the real use for them it made total sense to me if used as an "add-on" so to speak!!
The mistake I see a lot of times is dudes trying to use it when they are about to go on-stage (competing) to bring up a lagging part (usually rear delts, triceps, biceps) and it looks HORRIBLE since bodyfat is really low and you can see all the weird lumps where you pinned it.
The way I see to use it as a "tool" is to use it to bring up a lagging body part in the off-season!! Let's say biceps aren't growing like the rest of your body, no matter what you do, you have a hard time getting that mind-to -muscle connection, can't isolate them, shoulders take the brunt of the workload, etc, well that's when SEO's can work MAGIC to get them going!!
If you pin SEO that will make the fascia expand, so then let's say you pin biceps (hell sometimes pinning anything in this muscle will help you feel the mind-muscle connection as you'll feel the pump when you train it),the pump will be hellacious, thus making more room for your biceps to grow, plus getting all the good stuff in there as you'll be eating lotsa good stuff in the off-season so you are getting all the benefits from using SEO's at this particular time. Pretty soon your 18 inch guns will start to look like 20 inch cannons!!
I'm going to try SEO's next year as the stuff is expensive and plus, I want to give this off-season a good go at it to see if I can get my arms caught up to the rest of my physique as my shoulders overshadow my arms!! Thank you CH and DW for the good info!!