I didn't have the chance to hear the Spendor 100, but I owned the Spendor 9.2 and I now have the Harbeth Super HL5+ XD,
The Spendor 9.2 speakers have great qualities, among them: spacial presentation, dynamics, efficiency, speed, and they provide deep bass, and solid imaging as well.
I didn't like their tonal caracter though, to me they sounded somewhat thin and dry across the board more so in the mid bass area,
I now own the Harbeth and to me they are better on the tonal and timber side of things, they are less efficient but it isn't a serious issue for me, I run/ran both pairs with a Melco/Aqua streamer and DAC respectively and Luxman CF-6 and MA-600 separated preamp and amp.
I use them in a secondary system and for the money they are a tough act to follow, they took 300 hours of break in to lead to their full potential,