I know I'll get a lot of disagreement on this one, but it is my prediction that gold and silver will both crash within the next 15 months. I predict silver to go below $20 and gold to go below $1000. When it does, I'll buy junk 90% silver.
If I had a compelling reason to sell right now, I would seriously consider it. However, there isn't anything pushing me to do it, so I won't.
Trading silver to gold seems like an OK move. The only hit you take is the margin difference as was mentioned. I wouldn't recommend to anyone to buy fine gold today, but trading junk silver or even scrap jewelery for fine gold does make the most sense if you want fine gold. You won't find it hunting coin rolls, so trade your least precious pieces for that fine gold!