Are you a long-time Google Voice user? You might not want to sign up for Google's Project Fi service, then. Early adopters who've received an invitation report that you're required to give up important Voice features, including calls, texting and voicemail from within Google Talk, Google Voice and Obihai devices. You'll still get those options in Hangouts (if you turned on support) as well as call forwarding and voicemail transcripts, but you'll otherwise end up with a pale shadow of the phone services you knew before. That could be a worthwhile tradeoff if you like Project Fi's multi-network coverage and simple pricing -- just be sure that you're aware of the consequences.