Pioneer has recently released the BDR-212UBK, the BDR-2212, and the BDR-212DBK.
The BDR-212UBK is a 4K UltraHD Blu-ray reader which is also a BDXL burner. You must use a recent Intel CPU and its integrated graphics to play a 4K UltraHD Blu-ray with this drive. This drive ships with CyberLink Media Suite 10. Pioneer’s product description
The BDR-2212 is like the BDR-212UBK except that it cannot read 4K UltraHD discs. Pioneer’s product description
The BDR-212DBK is like the BDR-2212 except that it cannot burn BDXL discs, cannot write DVD-RAM discs, and it comes with no software. Pioneer’s product description
The main difference that I could find between this series and the BDR-211UBK is that this series apparently is able to withstand more abuse from dust and tobacco smoke.
EDIT: Spelling error fixed