FR I found the same to be true with the new wilson antennas. I tried to tune 2 of them, stuck my sirio performer up on the guys van and it dropped to like as 1.2, best he could get his was about 1.5-1.7, and the x and r readings sucked. I had an old wilson 5000 that was pre barjan or whoever owns them now, with a brand new whip and I was able to tune it to about flat at 27.385. We had to trim some off the whip but we would have with the sirio as well. At any rate he had 2 brand new wilson 5000 base coils with like 5 whips, a couple new ones and a couple that had been cut way down lol. I just installed a new performer 5000 on my work van after not being able to get the performer about a year or so ago. I beat the crap out of the turbo and it still works great but I like the performer better. Matter or opinion I suppose. Man if I could only drill my work van I would!! It's about 9ft to the roof. Add the sirio and your about a 15ft or so lol. It can talk out the back door with about 6ft x10dt of metal under the antenna behind it. Look up the Nissan NV 3500 high back work van you'll see what I have to work with. Even with the mag mount it rocks!! Just my experience with them.