I have a Tracker 18 all fish/90hp that does have a livewell right behind the seat post. I dont notice much if any difference in handling when it is full of water. This is a mod-V so maybe that has something to do with it. I havent had to worry about there being too much fish weight in there though! Cant say it is watertight cause it will slosh out if full while not on plane. It is not very user-friendly--it would be better if it opened from the front with a simple latch to keep it shut when on the big pully or towing. Have to pretty much get out of the seat and off the platform to open & toss in fish, but maybe yor layout is better. My being old and fat may be part of the problem. Something to think about if you install one.