In fact.. did you like this short story?

[Brice]

I didn't like it at all, except the very first pages (till he woke up in hospital). I found the rest long, boring, and somehow pointless - not at all like the rest of DT, which once again confirmed my opinion (firm to begin with) that the Dark Tower is a 7-volume book, not a "series".

Sorry, to hear you couldn't enjoy it.

I'll only point out to you though that this is in fact canon as it's part of the same story and was written and published before it was completed.