It was the best Club I've ever eaten. A few changes to the classic were great improvements.
When I used to eat meat I also made variations of clubs. I didn't think pickles worked in a club, and my favourite way to add some acid was with an olive tapenade.
I also refused to go anywhere near spinach (probably my least favourite leafy green). Romaine was still my go to for the crunch. I used avocado mayo most often (no pesto for me as I'm lactose intolerant).
One of the best things I've ever done to a club was to add roasted eggplant mash (not something akin to baba ganoush, just roasted and roughly mashed eggplant with finely minced fresh garlic & coriander leaves mixed in) as a secondary spread to the mayo (eggplant on the bottom slice and mayo on the top one). It really played well off of the smokiness of the bacon (go thick cut here IMO).
Lastly, heirloom tomatoes change everything, if they're in season and you can get your hands on the good, organic stuff.
Anyhow, these are my club sandwich cliff notes from memory. Haven't had one in years now.
EDIT: Did you toast your bread? I always toasted at least the soaker slice so that it wouldn't disintegrate too much from all the juices running. I'm not a big fan of toasted bread though. Unless it's that nasty, under-baked stuff they sell in plastic bags at supermarkets.