On the guressing game the same as Sam - corked second time round. Seemed more mellow second time. Thought the golpe might sound louder but I didn't notice any difference. Can't comment on technique, can only say I enjoyed listening.
Would be interesting to hear something with powerful ras. How about a nice Tangos
The ports surprise me as I would have imagined one would apply a patch on the inside prior to drilling and the patch would be the reinforcement, but it looks pretty clean cut the way it is. Interesting experiment and I guess if builders go this way fairly soon the ports will seem quite normal.