In steelhead fishing, we cast 10 to 12 foot rods all the time with litte issue. In fact, in my opinion, when bank fishing, I would prefer a longer rod. Reason being is you can cast a float set to a deeper depth (not a slip float) and you can have more slack line out. Shorter rod equals less leverage.
Just a little background on rods. I build them all the time. A light weight fast action rod from one company can and will be different than a light weight fast action rod from another. Several factors make this up but the biggest is the composition of materials used to build the blank. Everything from fiberglass, carbon fiber, graphite, and everything in between. Not to mention the resin used to put it all together. And don't get me started on blends.
You did the right thing. Go and find one that feels the best in "your" hand. I build rods for people all the time and personally, I would never fish with it (don't like the feel) but they love them. We are not all alike! I would purchase the 8 footer. Worst case scenario is you find a flaw with it and are forced to go and "add" to your arsenal!