I guess that some reasons to not use an extender are:
At first there were in the market only expensive models, but now you can find really cheap ones on ebay.
You’ll have to have a certain flaccid glans size to keep the penis in the device, but you can find both extenders with just the silicon noose tube, or the strap-type fasteners which should be better, and some use a velcro-type fastener.
It does take many hour to get comfortable with the tube noose model, but with a good wrap around behind the glans should do the trick. Start out easy regarding traction and time. I use the Jes-extender, and it can give traction from 600-1500 grams. When I started out, I took it easy and increased traction from minimum to max during 4 months, and I’ve been using 1500 and 1200 grams since. I did use the extender for two years, but took several years off PE. I started up again in march this year and used right away the same length on the extender. ( I recorded just over 2000 hours/average of 4 hours per day during those two years, and gained 1+1/4 inch in length)
I did jelqing in the beginning, but I felt my penis would grow wider, and I wanted more length. If I get erected while using the extender, my penis is so wide (and»flat»), that it barely fits between the rods and the base ring. So I think I have enough girth.
Good luck guys, keep growing.