IME acid has alot more body load like extreme muscle tension and jaw clenching, whereas the mushroom can be alot more head screwy, depending on your respective dosages of course. But acid can be "fun" alot more than mushrooms, mushrooms always seem to take a spirtual tone with me. On acid I will like the hippy from south park with the "legalize everything" t-shirt "hehehehhe I am totally tripping hehehehe" whereas with mushrooms I will be more like "Life is amaaaazzziiinggg whoa, [looking at a fence] this fence means everthing hehehe." Dont take those examples as absolutes though it can all vary, thats just my general reaction.
If I had to suggest one, I would have to suggest both, first try about 1.5g of mushrooms, then when you feel ready try a hit of acid to find out which one you like best.
Be safe and happy trails