My best effort on Syncopia is around 70 perfect in a row. The thing is not to worry too much about the odd mistake and just make sure you do the next zone or lap perfect. Its pretty hard to keep concentration for close to/over 20 minutes so the odd mistake doesn't hurt and will help resharpen your focus.
To get through the first few zones I try to see how fast I can get to 100,000. Zone 27 is the quickest I've made it but I can never hit every speed pad for some reason. Then just do 1 BR per lap to slowly build my energy back up. If I make a mistake from subsonic onwards I don't do a BR that lap. I personally use this all the way to about zone 85/90, I know others will use it to beyond 100. Its just how comfortable you are about how far you can get. To me it feels a bit weird going round Syncopia with 100% energy, just feels wasteful !! However, from 100 onwards its very easy to make a little mistake that leads into a big one that can use over 50% of your energy.