Hi Crusty,
Yes, conservative Christians will visit the Vatican; just as we would visit a museum or an art gallery -- for the man-made artwork and beauty.
However, for spiritual guidance and strength -- the Vatican is not the place for a Protestant; at least, not a conservative Protestant.
LMM, you say, "I never got any thing out of that church" -- meaning the Presbyterian. Possibly, that is because the Presbyterian, Methodist, Baptist, etc., building is not the church. Nor is the Vatican. The church is the body of believers -- all Christian believers.
And, we can be found in many types and sizes of church buildings -- from giant cathedrals to small one room churches to private homes. It does not matter where we meet -- it only matters Who we meet.
God bless, have a wonderful, blessed day,
Bill