Blonder Tongue HAVM agile modulator?

[TheShanMan]

Wondering what the consensus is on the HAVM modulators? I get the impression that they're sort of low end modulators yet they allow you to pick whatever channel you want. I read a post here saying that they interfere with adjacent channels but I haven't found much else in the way of opinions/reviews of them.

I'm not concerned about interfering with adjacent channels since I'm only interested in having a single broadcast, but I really like the idea of choosing the channel so I'm reluctant to buy a single channel modulator. Any other reason to skip these units and wait for a "higher end" one?