I have tested your newest release "gnoboot-alpha10.3-vfat" on a ESXi 5.5 with RDM Mapped Drives.
CiFS , NFS, iSCSi is working!!
ISCSi gives a "kernel trace back" but its working!
Before i was on gnoboot-alpha5 with dsm5 4418 (beta) and the performance was awesome.. NFS 120mbs / CiFS the same and iSCSI arount 110mbs, but i need to say with "gnoboot-alpha5" the PVSCSI Drivers were working!! (VMware Paravirtual SCSI)
With the latest gnoboot-alpha10.3-vfat and Offical DSM 4458 on the same VM i needed to change the PVSCSI (VMware Paravirtual SCSI) to "LSI Logical Bus" otherwise the Harddisks were not detected.
NFS 50 -60mbs
CiFS 50 -60mbs
iSCSI: 30 - 50mbs
So i hope you can bring back the PVSCSI support and as Always: Keep the good work up Great Work!