Yes I did very early in my radio adventures, years ago. I don't remember how much we pulled the top section out , but we got the SWR reasonable and I ran it for almost a year before replacing it.While waiting on Gary to reply, has anyone else used the Ringo for CB?
At one point we tried loading the top of it with a fiberglass whip for the lower bands, that was a failure but I was a radio rookie and had no idea what I was doing ......
As for the OP, the answer is ,"It Depends"
If you are limited on space the I Max would be the choice, but if you have the room for a full 5/8 antenna with full length radials, I would consider the Maco best.
And with the uncertainty of the length and tuning of the current I Max models.....
73
Jeff