Probably Safer, unless you count optional bosses like the Midgar Zolom and the Weapons.
The first time I played FF7 I got stuck badly a few times and was ridiculously over-levelled from the Gold Saucer onwards, so most of the bosses people find hard were a walkover for me.
Since Sephiroth gets stronger when the player has characters at lv. 99, I didn't have KotR and I was used to bulldozering everything he took quite a while to beat. In fact, the first time I beat him was after I reloaded an old save and fought him when my strongest characters were at lv. 98 (perfect!); he went down easily and never gave me any trouble again.