I recently heard it was a brutal experience and have been thinking of trying it as a challenge.
Here is a list of the changes that were made in one of the balancing updates: https://pastebin.com/HxMjdaBx
Some of the notable changes were:
- Upgrade scaling buffed 5-20%
- Overall increase in souls gained (~2-2.5 times more)
- Damage reduced on some mobs?
- HP lowered on some mobs?
- Reduced acquisition range on normal enemies.
- Supposedly reduced poise on some enemies.
- Bosses drop Humanity and Homeward Bones
- Ghosts and Skeletons give souls now.
- Twinkling Titanite drop rate improved.
- Pyromancers in Catacombs drop Skull Lanterns.
- Darkwraiths in New Londo drop Dark Hand.
- Male Undead Merchant: Also sells bottomless box
- Female Undead Merchant: Sells Arrows / Crossbolts
- Andrei: Sells Arrows / Crossbolts
- Domnhal of Xena: Sells Arrows / Crossbolts, Master Key (5000)
- Giant Blacksmith: Sells Arrows / Crossbolts, Small Titanite Shards, Large Tit Shards, Twinkling (8000 per, inf amount), Green Shards, Repair box, upgrade boxes
- Vamos: Arrows / Crossbolts, Small Tit, Large tit, Repair box / upgrade boxes
- Inglwood: Sells Transient Curses
The biggest change that I remember was done to the bomb throwing giant in Sen's Fortress. In 1.00, he used to predict where you're going before throwing the bomb and it would really make the first few attempts to go through be extremely annoying and difficult. I loved it.