I'm around 50% on upgrades as well, as a diamond, and it was much different when I was gold. Suite upgrades happen, but aren't the norm. That said, I've received some extremely large rooms that have had much more space than some actual suites. Like others have said, it depends on the property, availability, length of stay, the mood of the desk clerk, the tides, global warming, and African Swallow migration patterns. Lounge access in the US usually only gets you a continental breakfast in the morning and snacks at night. Most upgrades come in the form of the "executive floor" which usually consists of slightly nicer or more recently renovated rooms. Views, balconies, and other extremely minor upgrades are common as well. What consists of an upgrade is entirely up to the property and the inconstancy is one of the majoy complaints associated with the HHonors program.

Many lounges are purpose-built and very nice, while some are indeed converted rooms/suites. If I'm with my wife I usually ask for breakfast coupons at the restaurant in lieu of lounge access... a hot breakfast for two is a much better amenity at most US properties. European lounges comonly offer more, but access is also often reserved for those actually upgraded to the executive floor.