Heck...if you're BAITcasting with a weight then go 30+# (why not?). You should be able to cast the rig far as heck. But, someone on this site mentioned a helicopter problem with fishfinders (I've had no major prob, but it does twirl around a bit). A (not sure the right word) rig that has the weight straight out and the bait to the side (triple ring swivel thingy)) might be easier to cast.
In any case, don't forget to use a swivel if you are throwing any type of bait (for example, 18 " up on line).
and, You can always get an extra spool "just in case" you get super ratted or in case you want to change from (say) heavy pound test bait line to lighter (but still heavy) lure line.
If you are new to casting the squidder then you are right to get rid of that "light" 20 # test right quick.
B.L
PS: Don't forget...if you have been casting (say) 2 oz tins for a while then switch to (say) a 4 oz lead sinker and a fish head then you are headed for trouble if you don't ease into it. The line/spool/your-thumb needs to take a few casts to get tuned into the varying weights.
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