"A friend who plays more tabletop games than I do tells me that — in terms of the mechanics — as tabletop games go, it’s middling" absolutely, just played my first few games of Infinity recently (yes plural each game took around an hour) and was blown away by how much more fun it was to play. The next day we were trying to organise the next session. That never happened with 40K because the games were exhausting and more something you 'got through'.

However as the author says Games Workshop have created an incredibly engrossing setting which pulls you in and enhances all the other aspects of the hobby.