i have the imax 2000 and the maco V5000 both at 42' currently and find no knock your socks off difference between TX & RX maybe just a slight edge on the RX to the V5000 maco. but of the two i like the Imax better because it's much more wide banded then the maco. on my Imax swr's stay below 1.5 from 26.7950 thru 28.5250. maco v5000 has no where near the band width swr's are pretty good thru the regular 40 up to about 27.5100.
I've helped a couple friends who went the other way and replaced their V58 with an Imax and got about an S-unit better performance from the Imax but also got more noise. One of the V58s was only a month old. Just do the new Penetrator 500 and be done with it for the next 30 years.
I probally would if I lived out in the country somewhere. But unfourntly I live in town and where I'm located at I wouldn't have any room for a set of beams. that's why I gotta stick with a ground plane for now. Which really sucks.