Hi Chris,
Essentially the demand has increased markedly over the last 3 months (I run a company printing 3D designs for engineering companies).
Because of that and also, the very small, but important requests for larger models has made us buy the Ultimaker S5.
The 3 is an excellent industrial printer, but for the 5% of inquiries that come through needing a larger print volume, we needed to move up.
Thanks
Joe