OK.
First of all, I wouldn't recommend this for bubble hash, unless it's "full melt" bubble hash, the top quality. Melts when exposed to heat. Otherwise, it wont vape.

Secondly, yeah the Yocan XL is ok, but wasteful. Also, since I've found the Sai TAF , I haven't used any other vape.

By the way, the Sai coils fit this device, according to my friend. I have not purchased this yet, but may.

You can find the Sai coils here . I am not a part of the company.

Also you can find the Sai TAF there.

The Sai TAF is revolutionary in that it has a cup. No leaking. I myself got the quartz cup for superior flavor. It's just an enail in taste and delivery.

Enjoy !