It seems to me there are some dialogues or scenes which seems to be made (or thought) very hurriedly (ironic, if we bear in mind the screenplay had a large process of development). But it's the sensation I get sometimes from some scenes. Like if they shot them conventionally and more like "the nowadays", if I'm explaining myself well. Maybe I'm wrong, but I find the other movies to be a lot more carefully thought out. Each scene seemed to be very much studied and inspired.
I think the artifact is O.K. I like the mysteries and the topics about UFO... But it's the movie itself the one it has some lack of inspiration in some places (I opine). Even I didn't like the artifact, I think it won't be a problem. They didn't deepen too much in the topic of Shankara Stones, but the movie worked very well because it has good scenes of tension, action, fun and great moments with Indy.
If you look close enough the first half of the movie, you will see there is more dialogue, more interaction between characters and more "classic Indy spirit". But, in the second half, neither there was so much dialogue nor there was than interesting. The personal interaction was almost gone in the second half. Everybody acts like a cluster, a group run ahead, but there almost isn't personal moments or interactions. Even, the few there was, haven't passion or emotional connection. Indy movies were never cold and distant, and that may be a reason because this is a little different. I like it and I think it has great moments, but the inspiration isn't that alive. Maybe everybody (George Lucas, writers, Spielberg, Harrison, etc) wanted many things and, at the end, the movie didn't got a concrete personality but a mix of them.
Anyway, even with some little "buts", I think the movie was better than many movies of that year, and I think if you look at it like a chapter more in the saga, it's O.K., funny and with some great moments.