10' 7 weight or keep using 9' 8weight?

How can anyone else answer for you if it's worth it?
 
You've tried both, and are the only one who knows how they both felt to you.  Is it worth it?
 
If price is the issue, then you know that not all rods at all price points are created equal, so again, it's tough for someone else to tell you that because you liked rod XYZ that all 10' 7wts will be suited to you.  The only thing you can do is try them out.  I know guys that love fishing rods that I wouldn't every choose to use, and would sell if I somehow ended up with them...likewise, other guys have had similar reations to rods of mine that I'd let them use.  
 
My only experience here with with the 10' 7wt Echo Ion.  It's my current steelhead rod, and other than fishing some tidal flats a few years ago, steelhead is pretty much the only thing it gets used for.  In that purpose, I've yet to try a rod that I feel is better suited to the task for me, but again, everyone's different.
 
hopethishelpa

Love my 10' 7wt

I have a 9'6" Avid by St.Croix. I purchased the rod the same year St. Croix stopped making them.I love that rod.The extra length gives me more flexibility and is very sensitive for when the bite is light and as said above,tippet protection and can hog in a larger fish without worrying about a hog breaking you off.But if it feels good in your hands and lands you fish,go with what you like.