Yes, Bomret's is nice. I also like Detailed Terrain. No impact whatsoever. DT actually seems smoother than Bomret's normalmaps. Kinda toss up for the two on my rig. Though they are the best to not mess with RAEVWD. Vibrant and MGTR will make your head jerk when you transition from LOD to near. But you can really go without...just make sure you install RAEVWD cuz is the bombdiggadee.
I should prolly say that my monitor is 32 inch at 1366x768. I am pushing AA and AF @ 8x with no shadows, forced HDR and bloom (magical with All Natural weather, truly) At the moment, I get some amazing 25-55 fps (outdoor and indoor) averages. I ran through an Oblivion gate, came outside and ran down the hill to Chorrol, the weather was like WOW with the fog transition. I sped them up only a tiny bit. But the colors were crazy cool. I sat there, had to go fetch my brother and show him. He lives a few miles down the road. When we got back, there was a sunset and it starting snowing. Like it was so cool. I felt like the YouTube "Double Rainbow" guy. Made me weep, no really. Sit up in the mountains, watch the dawn hopefully you get a fast fog pattern. IC looks so cool with all the reds on the tower, oranges in the fog. Frikkin see Chorrol from Skingrad if you jump high enough,

Its like good times. 8D