Loading and teleports are definitely slower than they used to be. Especially in areas like the lumber yard outside varrock.
When I'm doing clues and use a lumber yard teleport scroll, I'll often be able to walk all the way around to the side of the lumber yard next to the gap in the fence before the fences load in (loading screens turned off), whereas before, the fences would load in much quicker and I could bladed dive to get to the gap in the fence. It seems to be kind of random though, sometimes the fences appear immediately after teleporting, other times only the ground texture shows up for quite a few seconds (enough to walk all the way to the gap).
It isn't exclusive to that location, but that's just where it's been most noticeable for me. Often only the ground texture will load in for the first few seconds and no objects or npcs will. Another is if I have my grace of the elves necklace attuned to the overgrown idols teleport, use that tele, and then dive/surge east, I'll be waiting for the gnome glider npc to load whereas previously he would already be there before I surged.