This was a "forced" upgrade of sorts, after I recently lost my Discovery 640. To state the obvious--I liked the 640 enough to buy the 655, and of this much I'm certain: a couple of weeks with a wired headset makes you appreciate Bluetooth all over again.

So how does the first gen 640 analog stack up against the third gen 655 with DSP? Well, if you're expecting the 655 to simply be an overall more refined 640, then you won't be disappointed. But if significant improvement is your benchmark, especially in performance, then you may want to wait for the 660 or whatever's next.

The sculpted shape of the 655 is a very distinctive and stylish refinement of the 640 body, and I find it handles better, especially when turning the unit on and off. Buttons on the 655 seem to be somewhat stiffer (apart from just being newer), but they're not too stiff by any means. On the plus side, I find that I no longer overshoot the "on" position, ending up in pairing mode.

As noted by others, Plantronics finally got the holster fit right: the 655 seats snugly and won't fall out. When it comes to the fit of the ear gel, I notice no difference between the 640 and the 655--they feel the same to my ear. Which is fine with me, since I never had a problem with the 640.

Also judged to be roughly the same: incoming call quality. Very good to excellent with both models. However, a significant negative for the 655 is the noticeable delay in connecting to an incoming call after you've pushed the button. I often catch callers in mid-sentence (they think that I'm already on the line) by the time the 655 finally connects. This delay doesn't exist on the 640. What's that about?

The jury's still out on outgoing call quality--the 655 is certainly as good as the 640 (which is to say that it's very good)--I'm just not sure it's any better. Those I call still seem to know easily that I'm on a headset. (Or ask, "Where are you calling from?) And in test messages that I've left myself, my voice is clear but has a pronounced "digital" quality to it. I'm going to do more tests under adverse conditions to see how much the DSP helps vs. the hype.

I don't miss the metal carrying case and mulitple charging adaptors that were included with the 640 but not the 655. The 655 has the one adaptor you need: mini-USB. An even nicer touch is the cord that lets you recharge from your PC's USB port. There's also the AC charger and adaptor, plus the AAA battery charging adaptor. But as with the 640, I continue to feel that the 655 has too many parts--increasing the risk of possible loss, or the likelihood that you won't have one of them with you when you need it for recharging. I called Plantronics to see about buying a second holster and USB adaptor, so I could keep them at work. But the price was $40, which is outrageous, especially when you consider that a new and complete 655 is down to $76 at thenerds.net. I'd love to see the mini-USB port incorporated into the body of the 655 itself, so I wouldn't need the holster or adaptor for recharging. The AX-2 uses such a design, although it's mini-USB port is a custom size that's even smaller than standard.

I also wish that Plantronics would stop with the bogus claim, "up to 10 hours of talk time." That's nonsense. After 3.5 hours (your actual mileage may vary) you MUST recharge, period. And yes, with the AAA charging adaptor, you can get up to two full recharges on one AAA battery (hence, the 10 hours of talk time)... but you can't talk while you're recharging, so it's not "continuous" talk time. And that's deceptive. What Plantronics SHOULD claim is that the 655 features a "wireless" recharging solution. That's cool, unique, useful... and it's true.

charlesn, thank you for the very good review of the 655. I also lost my 640 several month ago and purchased the 645. The time to connect on inbound calls drove me crazy. So I put it away and went to the Nokia BH-900 but I am having all sort of issues with it.

When I saw the 655 I was hoping it would be an improvement to the 645 but does not seem that way. I can't believe Plantronics did not fix the time to connect issue. Also, I did not see much of any improvement in background noise cancellation with the 645, unfortunately.

I will wait for the next generation, 660 or what ever they decide to call it.

Thanks again for the review.

Have to say without know much about any of the bluetooth headsets I lucked out with the 640.

Fit is fantastic, I can run without it falling out and this is without the earloop.

Sound quality is great. I have only used it with the unit on my hip.

Components, AAA charger ***** (5 star), holster/clip haven't had a problem yet, got up to 100mph on motorcyle with clip in my shirt pocket with earpiece in holster. Probably won't do it again . Already had usb cable from BB to charge. Adaptors great idea. Ear pieces, I use the largest one.

Connection time has not been an issue.

Charge time... usually have a cable nearby or AAA charger. I rotate between a couple rechargable AAA batteries.

Love the vibrate feature when unit is in holster, even works while not charging.

If I lose this one I would definetly get another 640.

Ben

Not sure if this was the case with the 645, but you can turn off the DSP on the 655. I'm going to try doing that and seeing if it clears up the delay issue. Not that I would consider this a fix--disabling a main feature to get it to work properly is a little ridiculous. But I have to think that DSP is the issue, since that's the only difference between the 645/655 and the 640, which had no delay. I'll report back with results.

Great idea, I am still battling with Plantronics on this issue.

I am going to wait out a bit more-truth is I am extremely happy with my 640 which I use with my BB,Treo and RAZR.In fact I lost my 640 a few weeks after getting it and went out and simply bought another one.The second set that I bought had the charging adapters for my other cell phones so it was cheaper to buy it that way than to buy a new headset and the charging bits.

I agree that Plantronics should tout the charging via AAA battery but not claim that it has 10 hours of talk time.I was initially under the impression that while charging you could talk-nonetheless I always carry the AAA charging bit in my briefcase,purse or pocket with a fresh AAA battery just to be sure.

Does the 655 have the ability to be paired to multiple devices simultaneously ?

I dont think it has the multi device capability....nor did turning off the DSP have any effect on the delay. I am swapping the 655 out for the 640.