I favor the Fountek CD2.0 or the Aurum Cantus G3 true ribbons for most line array applications. Their higher priced/larger brothers in each line can be used for severe power handling applications. The Fountek tweeters have plastic cases while the A-C tweeters all have cast metal housings. The housing difference accounts for most of the cost difference between these two brands. The ribbon tweeters have higher sensitivity ratings (upper 90's dB SPL) so they are easier to pad down a little to match the output from a line of mid-woofers. The B-G Neo 3 and 8 series have low impedance (4.0 ohms) and are low enough in sensitivity that designing to a passive crossover from a line of midwoofers get difficult as the woofer line is often more sensitive than the tweeters. The B-G Neo 8 and the longer B-G planars roll off over the 15-20 kHz area so they need a super tweeter to hold up the response.

Distortion tests don't reveal the true possibilities for ribbon tweeters used in line arrays. That is because you have power distributed to 8 or 9 devices so power distortion levels are very, very low vs. single driver measurements. For example you can successfully cross the Fountek Neo2.0 and A-C G3 ribbons as low as 1500 Hz in lines of 8 or 9 devices without audible distortion for home listening conditions.

By the way, an OEM version of the A-C G3 called the G3i-130 maybe available from some suppliers at a lower cost than the regular G3 without significant performance degradation.

Jim