Tell us what you've been "reading" and I'll tell you if it's really true. Cause if it's anything about the superb call quality, I call BS.
The ringer is slightly louder (with the same MP3 I used for ringtone testing) on the Fascinate than the Droid X. The speakerphone is also slightly louder. The Droid X also drops a lot more than the fascinate in ringer volume when you set it down on a flat surface - even worse on cloth, such as a couch or car seat. I tested this out extensively with both phones side by side.
Bluetooth performance on both devices is excellent for me so far. The call quality using the handset (not bluetooth) is notably better on the Droid X, for both the receiving end and the sending end. The fantastic reception of the Droid X combined with arguably one of the best mic systems put on
any phone
ever combine to give it the edge over the Fascinate in call quality.
That said, however, the Fascinate (at least my Fascinate) is not bad at all for call quality. The reported echo happened only very rarely for me, and it was short lived. Even while driving or in noisy environments the Fascinate did fine. I think the Fascinate is good as a phone. The Droid X is phenomenal as a phone. I don't get much weird vibration or reverb issues either, unless I absolutely crank the volume and it's a loud source on the other end (which usually meant it was too loud to be comfortable for my ear anyhow.)
No reception issues with either phone, even in a basement where my Omnia has dropped calls, the Eris dropped calls, and a few other phones I've tested will intermittently drop. The Fascinate hasn't dropped a call down there yet, but the signal strength is 10-20 db stronger on the Droid X. Again, no surprise.
One thing that I have been basking in all day is how much more comfortable the Fascinate is to hold up to my ear for long calls w/o the headset. The Droid X might sound better, but it's not as ergonomic nor as easy to operate as an actual phone. It's just less smooth, more square and bulky, and heavier. Those aren't actually bad things for a smart phone you want to be durable, until you have to hold it up to your head all day making calls!
Anyways, those are the results of some more extensive testing between the Droid X and the Fascinate simply based on phone performance. When it comes to overall quality, at least in my testing, the Fascinate is good. The Droid X is great! Just my two cents.