Probably would. Firstly you need to time Siebel ordering and it can be cut fine, leaving you in a panic if you've got the session organised. They try and send so it arrives fresh but any delays with the postal service can **** things up for you. I signed up to a session that was postponed due to this.
Again due to shelf life but I have experienced some siebel taints showing less than expected flavour/aroma, despite being manufactured and posted fresh.
Secondly the aroxa are super easy to use and (shelf life again) - if you have any left over you can store and organise another session. There are a lot of slightly odd additions to the siebel which, while interesting, are quite uncommon and taint sessions really do require time. You will very likely have leftovers from either kit (or a very long session).