Yeah, I forgot to answer those
To be honest, I'm not sure on how much RAM the ROM consumes. It must be less than the resource hungry Sense 3.x builds, for sure, but I'm not sure in total. It's probably fairly low.
I don't recall having any problems with black screens or the phone hanging, but it has been a while since I used the ROM so I might have just forgotten about them.
Same with the voice echo - I don't remember it being there, but I haven't used the ROM in a while and also I don't actually make phone calls with my phone all that often so I may not even have made any calls whilst I had it. Actually, as I'm typing this I do remember having a minor voice echo issue with one ROM that I used, but in the past months I've tested a lot of ROMs, so I really can't tell you if it was this one or not.
Finally, advantages and disadvantages:
The advantages basically are just that it's running ICS. I'm sure somewhere you can find a list of reasons why ICS is better than Gingerbread but overall it feels better thought through and it definitely looks really nice too.
As for disadvantages, (comparing this in my head to NexusHD2-Gingerbread, but I'm sure it's a similar comparison with other 2.3 ROMs) it's a bit slower, less stable and there are some features that don't entirely work, such as the camera being a bit flaky still. Basically, if you want the cutting edge for your phone then this ROM is good, but if you'd rather have something that's stable and works a bit better in general then grab a Gingerbread ROM (or stay with a Gingerbread ROM if that's what you have at the moment). I think the battery life was about the same in ICS. After all, the kernel I'm using works for ICS builds too so there's probably not too much difference between them.
