He's on 7.3 EhP1, which is on SPS12 today. It got pretty stable by SP08, SP09. SP05 was pretty early on, and had a lot of bugs in the HANA views.
7.4 is on SP07 like you say, and most of our customers run at least SP06 - before then, you had to apply a bucketload of SAP notes. I would recommend customers apply SP08 with care because it's a feature release so will have a bunch of new features, which will no doubt need corrections.