Be Careful on the corporate versions, some of them have excess, the plan you are currently on, i plan level 2 is now classed as an older plan and the hospital plan level 2 is the new plan. there are no big differences on it, some of the Hospital benefits are actually better and the price of course.
But if you use the HIA.ie site to compare the 2 plans its easier to understand than aviva's own site would you believe! Once you see the word "Hospital" on your plan it means there are no everyday benefits on it, like GP visits, thats why they have plans called "Everyday" also.
It might also be worth looking at the Hospital level 1, there are few differences to the benefits between 1 and 2. I consider myself to be in good health, not having kids in the future, so i switched from level 2 to level 1 to make further savings, this was due to my partner losing his job, we couldnt afford level 2, so rather than cancel our health insurance we reduced it down. We have both been unlucky enough to claim on this policy this year, it covered, scans, hospital stay, surgery and consultants..
With regard to the semi private and private and full cover words, the I plan covered you for all private and semi private, the hospital plan still does that, but they have broken it down and explained it a little better i think.
You still have the same cover, Private Hospital you get a semi-private room rate which means you have to pay a portion,
Public Hospital you get a Private room... (now the big thing about this is even though your insurance covers you for a private room there are never private rooms available anymore due to isolation etc)
Hope this helps