I have a rod setup for jig and plastics. I was using stealth braid, but it does not manage well, it digs in line easier. I was using 30lb line but was thinking 50lb 832 would help with the line digging in. What is the disadvantage of 50lb vs 30lb?

Exactly what you said, reduce digging it. It just handles better on a baitcaster IMO. You can fish 30lb without a doubt, but I prefer the larger diameter line. 

I knew it helped with digging, but what is the disadvantage to using much higher lb? Shorter casting length?

I knew it helped with digging, but what is the disadvantage to using much higher lb? Shorter casting length?

A little less line capacity which could slightly effect casting distance. It's a little thicker so possibly a little more visible to the fish and a little stiffer. 

Make sure that you put your new braid on very tight. A little finger tension doesn't cut IMHO. Run it through a couple of phone books,yes they still make those, if you have any or anything that can put a good amount of tension on the braid.

I don't understand all of the suggestions to spool braid so tight. After the first long cast you've lost all of that tension. I spool braid like any other line.

I've used 50lb 832 for quite some time and it's perfect for what you need. I don't get line dig and it's just an all around great braid.

I've got 30lb test on my diawa tatula and I use that for flipping, pitching, jigs, and plastics. I had 50lb on but it needed respooled and I didn't have more 50lb so I settled for 30lb.

Honestly I'm kinda liking the 30lb, it slices through the grass and pads here really good and it really doesn't dig in that bad...

50lb will be fine though and it definitely digs in less than 30lb, but IMO 30lb is more versatile and thats what I need in the lines I use atm

50lb test will have less dig in esp when your setting the hook hard with the drag locked down. I have two reels that have stealth braid on them and they have done good so far aside from the color bleeding out over time. Have had no break offs and the 30lb test has done very well for me fishing frogs, soft plastic toads, and light to moderate cover. My 30lb line has dug in much less after its been used and soaked up water over time but at first there was more dig than the 50lb test. I offset the dig in by backing the drag down some and that helped out.