I've downloaded & installed it 2 different times successfully from Bandlab Assistant. (Serial number stayed the same both times).
1st time was from Bandlab Assistant on a Win7-64bit image with Sonar X1 Studio & VS-100 USB audio interface. Ran a few of my VST-heavy test Projects-No problems. After a couple of days, realized I didn't need Sonar X1 Studio any longer since I never used the few free extra goodies it came with, so I Revo-Uninstalled it, CbB, & Bandlab Assistant. Spent an hour or so cleaning Windows & the registry.
2nd time I installed directly from the Cakewalk.exe file I saved from My Downloads, but CbB was in Demo mode. Revo-Uninstalled it, cleaned registry, CCleaned, etc.
3rd time I (correctly) downloaded & installed it from Bandlab Assistant (like the 1st time). Serial number is the same as the 1st install.
Lots of improvements from X1 Studio. I'm on a quad-core laptop from 2012 so sometimes I want to use it outside and don't want to lug around my audio interface & MIDI keyboard. With onboard audio and WDM KS driver mode (or ASIO4ALL, which is just a WDM-wrapper), Sonar X1 was a mess-high latency with underruns and dropouts all the time so I never bother going 'portable' with Sonar X1. With CbB I can use WASAPI Exclusive driver mode with low latency & high reliablity with the onboard audio, finally.
Plus the other tweaks and improvements from 6 years of development from X1. Learning about the new features like Ripple Edit, improved Audio Snap, & Groove tools, Matrix View, etc. GUI improvements-it is easier to navigate too despite having more functionality than X1. Plus just having a QWERTY virtual MIDI keyboard is great.
It reminds me of why I never bothered upgrading beyond Sonar X1 Studio - I wanted all of the core features of Sonar Platinum, but didn't want the extra 3rd-party goodies since I have most of the Waves plugins and a boatload of soft synths already.