CathyG ,
Nice thing about a 10' rod is that it does most everything else in spades,Besides the ability to control dragfree drifts within your abilities.It also gives you way more in the department of larger fish fighting capability...most 10 foot rods have a heavier butt to the rodd blank an when you need that extra stick you can use that to your advantage and get a fish in a lot quicker,and that means theres less time playing games an wearing that fish out an building lactic acid up in its system...therefore the fish will be happier.
The Cortland Brook 10' 4 wt will throw streamers, but for a happier medium including streamers, bigger water go with the 5wt.
the 4 wt is a great stick too, but IMHO on bigger water an throwing bigger flies also dealing with windy conditions that tend to happen far more on bigger water because its more open, a 5 weight is a better option,nice thing too is that you can always underline the rod an use a 4 wt line or go line size larger with a 6 an be perfectly fine..well maybe a lil adjustment in your giddy up..but a few minutes an you'll be fine.
Cathy if you want we cann mett up on a stream an ill let ya use the rod for the day an you can make a decision before you buy one.
Tight Wraps & Tight Lines
Rick Wallace
BTW aside from my 9' 9weight Gloomis GL4 i use when Salmon are aound, I strictly use a 10' 6 wt on the NY Great Lakes Tribs an land numbers of Browns in the upper teens no problems...also have landed my largest brown 21 pound hen on a Winston LT 5 pc 6wt .That was no fun, the rods was strained but delivered.I prefer 10' rods an larger for all my medium an river fishing these days.
I can Thank Ol Lefty {Dave Rothrock} for that advice. he turned me onto larger rods,before that longest rod i owned was 8' an it was a Gloomis GL3 4wt, rod i used constantly was a 7'6" 5 wt, an my current small stream rod is a 7'6" Hexagraph,and that same 7'6" 5 wt,also a 7' 4 wt.