Jon might be right, but I think it is obviously still important to figure out what that elusive "flavor" thing is. I wouldn't have thought that mouthfeel and the aqueousness of a brew could be construed as a deficit in flavor, but everyone's taste buds are different.
If you are using liquid malt extract (LME), which is the cheapest extract way to go, definitely check out what is in the extract. I don't see LME on the ABS site, but I know lots of the NB extracts already contain carapils in them. Wacht out not to overload with that by adding more to the steep. Malto dextrin has definitely always worked for me.
This is a good point.
Wahoo, one thing you may want to do, if you still have some of the brown ale left, is to buy some commercial versions of the style and compare them to what you brewed. You may find a big difference in what you brewed to the appropriate styles, or you may find that the style is not to your liking. It looks like after you made one watery beer, you started making 4 gallon batches.
Also, if you need a great dry hard cider recipe:
5 gallons apple juice (with no preservatives)
1 packet red star montrachet wine yeast
add all ingredients to a 5 gallon carboy, put airlock on (fill almost all the way to the top, there won't be any krausen), wait 6 weeks...it should get very clear. it's now ready to bottle or keg...it will be delicous when it has fully carbed. If you add 2 lbs of dextrose to the ingredient list you'll get the famous "Edwort's Apfelwein." I like the less winelike, lower alcohol version better.