We have a busy call center running 12.5. About 20 queues. 10k calls per day. 125-200 concurrent calls, all day long It took a bit of work to get this properly operational about 3 years ago. But it's been stable for some time. We now need to upgrade to 15.5, for obvious reasons. This makes me nervous. I have no clue how well the new 15.x platform performs with the aforementioned load. (Server hardware not an issue.) Does anyone have a 15.5 system running with a similar load, or bigger? Any feedback is highly appreciated. Thanks.