I've been extremely happy with my FPVL antennas...been as far out as 3500 feet and I'm sure I could go further in a fully open area. However, regardless of what you get 3rd party (at least without a signal booster) maintaining video through treelines even with intermittent LOS, your video signal will drop out long before that. I'm definitely planning to add an exterior antenna kit at least as good (no, better) than what the H Pro now comes standard with. I talked with Yuneec CS to inquire if they plan to at least offer an upgrade kit to bring us up to the standard of the Pro ...even for purchase to upgrade the antennas for we early adopters (i.e. beta testers). The response was, "it's been discussed, but doubtful". So, I for one am not holding my breath and am certainly watching and hoping for a good 3rd party upgrade kit, hopefully one that's amplified for telemetry.
I'll just add before someone jumps on me: I'm not interested in flying farther than LOS...but I do want to be assured I'm not going to lose video when flying from behind a treeline, which can be a very regular situation here in Tennessee.