I just got the 680 and it is working fine. A couple of minor tweaks were needed, but I was able to call support and get someone on the phone in 5 minutes or less. Everything looks to be working fine now. I looked at the 880, but didn't see enough benefit to it to justify the extra cost. I was considering the 676 as well, but found a deal where the 680 was about $40 less, so that made the choice easy.