My system:
i7-4790K, 16 GB RAM, SSD Samsung Evo 1 TB SSD, 2 x Geforce Titan X SLI, playing on Win10, newest Nvidia Win10 driver, 100Mbit/s fibre internet connection, all appropriate ports forwarded. Visuals set to ultra with max particle settings which did not cause any issues before you came up with your "performance patch 1.7".
...and no it does not matter if I play with (only updated) addons or not and it happens not just in crowded zones but everywhere, even in 4-men PvE instances.
Only relogging is able to cure the above issues for a while (besides the annoying loading screens, those are always there).
Playing feels like a roll back into the stone age of PCs.
Sometimes the prey turns and nips us... it's a small thing.
So let the snow flakes and unicorns dance alone until they melt or vanish from existence, we will finish up with those smart enough to stay in the glowing circle of love.
Selissi - CP 1k+ Redguard Stamina Nightblade (Ebonheart Pact)
Silmerel - CP 1k+ Breton Magicka Templar (Ebonheart Pact)
Sunja - CP 1k+ Dunmer Magicka Nightblade (Ebonheart Pact)
Suldreni - CP 1k+ Dunmer Magicka Dragonknight (Ebonheart Pact)
Sulhelka - CP 1k+ Altmer Magicka Sorcerer (Ebonheart Pact)
Sylundine - CP 1k+ Breton Magicka Warden (Ebonheart Pact)