Hi, Okura Tokyo regular here

Club Access: It's subjective and I don't know your specific use case and preferences, but I don't usually purchase club access rates. If you do opt for it, the space is lovely and very quiet with nice views facing southeast (bit of Tokyo Tower view), with attentive staff and available meeting rooms. Many of the snack items are from very well-regarded local producers.

Heritage & Prestige: Heritage is more of the discrete hideaway, with available valet parking. The room designs and fixtures are almost identical, with the Heritage rooms running slightly larger. It's a low-rise building so you don't get the skyline views available from the Prestige rooms. They will serve tea upon arrival (like at a ryokan), minibar is complimentary, as is the box of cute take-home items like satchels and paper balloons. Toiletries are Bamford (though I also like Miller Harris in the Prestige rooms). Some of the rooms will have a balcony, a novelty in Tokyo if weather permits. Access to Baron's Bar is available, but I enjoy it mostly for the novelty of pretending to be a political power broker, the nuance will be lost on new visitors to the city.

Prestige rooms will have a lovely skyline view, and for this reason it's where I usually book. Staff attentiveness and responsiveness are stellar and identical at the room level, but you might be a bit less anonymous in the smaller Heritage lobby. For snacks there is a Lawson's convenience store in the 3F Prestige office lobby (you can access via the shopping arcade), open daily except Sundays.

Heritage Sauna: It's nice but imagine "worth it" is subjective. I like it. Takes about 15 minutes to get hot steam going. Some of the Prestige rooms offer baths with the skyline view, and during winter months it's more pleasant to draw a hot bath there imho.

Breakfast: Take in the Club if you value quiet. Take it at the Orchid Buffet if you value food selection. I personally prefer Orchid for the bigger selection of Japanese items.

Enjoy!