No you are not alone. We upgraded from Versions 4 to 5 and it’s noticeably slower in playback and rendering performance. Also it take A LOT longer to add or remove the effect from a layer. We are talking about 10-20 seconds. I’ve contacted their support but they can’t give me any clear ETA when and if it will be fixed. At this point I’m considering going back to V4 and cancel the subscription until they sort out their things.
BTW Being bought by Maxon was probably not a good thing.