please try to boot with a floppy disk; attach the hard disk at runtime with the MESS on-screen menu (File manager -> Harddisk 1). Type "DIR HDS1." and see whether the hard disk can be read.
As I said, there is no particular reason why your hard disk should not be bootable with 0.147. I am using the same image for a long time and my Geneve *does* boot (after I converted my image).
The fact that you experience problems with other emulations seems to be an indication that something is wrong with the conversion.
Check your image with chdman:
chdman info -i disks/hd/harddisk.hd
chdman - MAME Compressed Hunks of Data (CHD) manager 0.147u3 (Dec 11 2012)
Input file: disks/hd/harddisk.hd
File Version: 5
Logical size: 260,046,848 bytes
Hunk Size: 4,096 bytes
Total Hunks: 63,488
Unit Size: 256 bytes
Total Units: 1,015,808
CHD size: 240,185,344 bytes
Metadata: Tag='GDDD' Index=0 Length=35 bytes
As for your expectations for future releases there will be probably only minor things, since the emulation of the TI and Geneve family is already pretty complete. However, with 0.145 I have done a major rewrite of the CPUs with a proper READY handling, so we can achieve a better timing emulation (with the exception of the wait states during a memory access which I hope to add in the next weeks).
Nevertheless, there is always a chance that I discover errors in the code which get fixed with the next release. So if you manage to get your hard disk converted, again, I recommend to upgrade.