I think you've got the differences in the two designs pretty much figured out.
The E36 is simplier, has less furniture and is therefore lighter and more open. The v-berth doors were an option. The entire bow area under the v-berth is completely empty. The tanks are under the settees in the middle of the boat. The std tankage is better than average: 70 water, 50 fuel, 20 holding. The area outboard of the settees under the pilot berths is completely empty and great for storage. The salon table folds up on the mast so the center of the boat is wide open. The galley is fine and has good storage plus the usual Ericson custom built-ins for bar and dishes. There is a full size nav table which is nice if you still plot on charts and there is plenty of room for electronics (but a chartplotter at the helm is pretty standard now). The open plan really helps ventilation at the expense of private cabins. Here in the hot Chesapeake, that was major factor for me. The cockpit lazerette area is huge and extends into the transom and across to the qtr berth so you can access the steering and engine completely. The hull volume of the E36 is pretty large, but a lot of it is empty, particularly at the ends. Because of this, the boat is easy to sail fast and sails incredibly well in light air - another must have here in the Chesapeake if you want to get out and sail often. It easily sails with a 150 genoa in 2-3 knots of breeze. The boat has the room to add a lot of cruising gear, but as Seth says, the added weight is going to work against performance. On deck, generally all the E36RHs have great sail handling layouts from their racing days. I sail mine singlehanded a lot so I much prefer the bridge deck 7:1 (no winch) mainsheet and the main traveller close to the helm to the cabintop main controls on the E38.
The E38 with the 6'6" deep keel is pretty close in performance to the E36RH, rated a little slower. It has more weight in the ends and probabaly most of the boats have a lot more cruising gear stuffed in there as well. The shoal versions are a little slower, particularly to windward. The E38 interior makes a nicer place to hang out in. There's more furniture and built-ins. The two cabins are more private. I'd guess you'd need A/C in a hot climate to fully use the cabins with doors closed. More of the space outboard and in the ends is harder to get to. The cabintop main controls open up seating in the cockpit and allow a bigger dodger.
Common issues I've seen on E36RHs: smallish non-selftailing primary winches, usually Barient 28s, halyards and controls at the mast for racing - not lead aft, lots of non-selftailing winches at mast and on cabintop due to a lack of rope clutches, many old, beat racing sails and no new usable furling sails in the inventory (really, do you need a MATCHING Blooper to go with that 20 year old 1.5 oz triradial spinnaker!), wet decks and wet interior teak from leaking deck components and the neglect of just one previous owner. The only minor design isssue is a typical starboard list from a full fuel tank and an empty water tank. Once the fuel tank is full, it's going to take a lot of engine hrs to burn off 50 gal. I'm finally down to half a tank after three seasons.
The E35-3 is like a smaller early E38 (non -200 series, fwd head, no aft cabin). Sails nice, but slightly slower than a E38 with the same style keel. Very nice, slightly smaller interior. I raced on an E35-3 and we had a E36RH in the fleet when both boats were new. The E36 was in the fastest class and we were in the next class down. The E36RH is better in light air and easier to sail fast. The E35-3 has the interior advantages of the E38 except smaller and no private aft cabin. It would be a good, less expensive alternative to the E38. If you really like the E38-200 layout and want less expensive, the late 80s E34 has the aft head layout and is closer to 35'.
Mark
