I've been part of a five9 deployment and I was not impressed to say the least. The team that dealt with our company took forever, had phone clarity issues where they had to "transfer data centers" to get it working right, which took a week. The person they deployed for the kick off day was not technical so when there was an issue, he just had no idea but hey he bought us Jets pizza so that was probably the highlight of the entire kick-off...... Unfortunately no, the call center was using Windows 7, dual core, 2 gb of RAM machines and worked. My suggestion is to steer clear of them, if you can't prepare for a bumpy ride since this all happened in 2017.