I've had both the Spendor S5e and the S8e. They are great speakers. I've never heard the Devores.
I recently sold my S8es to keep a pair of Spendor's classic SP1/2E. The midrange tonality of the classic model is a little more accurate than the S8e. However, the S8e has better deep bass and is more comfortable at volume. (It plays loud but would not be the recommended speaker for a head-banger.)
For me, the SP1/2E is a better choice. However, if I listened primarily to pop/rock I would have kept the S8e. The S5e is a great little speaker and you can find them used at $1,000 or even a bit under right now so are a great buy. However, I'd really make a run for the S8e if possible.