The Amulet of Samarkand question

Personally, I'd say it depends on what age range you're looking for. The maturity level of Bartimaeus felt close to the 10-14 range (similar to Harry Potter or Percy Jackson), while Infernal Devices tended more towards 15-18. Personally, I preferred Bartimaeus, as it was a much more relaxed/comic/easygoing read.

I think they're for two very different audiences; age aside, there are certainly different tastes required for either series. I would vote Stroud over Clare. Have you read the Nevermoor series? It's not very much like either, but a heartening, jolly good fantasy series worth a look.