Sofitel or Hilton at Heathrow

Having stayed at the Sofitel a couple of times (for BA flights out of T5) having a little bit of a dilema for our upcoming flight out of T3 with Virgin. Which is in the best hotel location to navigate the hotel to check in route?
Got to say I really like the Sofitel and cost wise there isn't that much difference. Although I am a HHonors Gold Member so the Exec Lounge access is appealing but have never stayed at Heathrow Hilton before and reviews look bad!
How does the Sofitel Club Lounge compare to the Hilton's? Anyone had any experience of either?
All advice greatly received
Thanks,
Steve.
Got to say I really like the Sofitel and cost wise there isn't that much difference. Although I am a HHonors Gold Member so the Exec Lounge access is appealing but have never stayed at Heathrow Hilton before and reviews look bad!
How does the Sofitel Club Lounge compare to the Hilton's? Anyone had any experience of either?
All advice greatly received

Thanks,
Steve.