TXJHawk,
I just recently upgraded to a PT 185 from my earlier PC 175. I upgraded to the 185 mostly because of room, storage, and stability. To answer your questions, and then some...
I got the 90 hp, up from my 50 on the PC175. It is not a rocket, but it gets nice speed (~48mph) at WOT. Also, the open gap spark plugs don't foul and it idles great. It does use a lot more gas than my 50, though...the 21 gal tank gets used up in a 6 hour day of skiing and fishing (the 90 also allows for some great ski fun when they stop biting!)
About stability, the wider beam than the 175 makes for easy one person fishing, loading and unloading. I don't notice any lateral rocking whatsoever, unless I move to the side and my 240 lb. buddy is almost standing on the rail in the back. Basically, it's not tippy at all.
About stability on the fly, I have noticed porpoising at higher speeds but a very smooth ride once trimmed correctly. I fish Lake Eufaula and the chop gets bad at times. We added a second console to the 185 for my wife...she now doesn't mind 6 am runs across the lake at 40 mph. That's a great addition if you don't mind losing the floorspace.
About gunwhale leaks...I only noticed it once when skiing, and only when I would pull the boat into a sharp turn, with the gunwhale almost below the waterline...only a little bit ran in and it was not disconcerting. I do have to run the bilge after pulling ski loads, however, but I think it's from everyone dripping off in the boat. Bottom line, not an issue at all.
Fitting in the garage...I have a standard size garage (if there is one, I guess) and have about 14" room left over in the front, with the motor resting on the transom saver. If I needed more room, I could tilt the motor full down and gain about 8". Width is not a problem if you have a fairly clean garage.
Would I buy it again? Oh yeah. It's a great package and provides all the storage and features a weekender needs. Like I said, I even earn cool points with the wife and kids by pulling tubes, kneeboards, and skis with the bigger motor. The back deck is perfect for the wife to lay out on, she just pulls up her seat and puts it down by her console. It has definitely fit all our needs.
Some recommendations of things that worked well for me: I upgraded my trolling motor to a 24 volt Motorguide Brute 56lb. The 43 lb 12 volt system was ok for my PC175, but for the wider and heavier 185, I wanted something with a little more meat. It moves the boat around very well, especially in the wind or thick weeds.
The second console is real nice on cool mornings...my next few upgrades will be a bicycle seat on the front with a hydr. pedestal and a bow mounted Garmin 240 (could we do a group buy on that, Ken?).
I think you'll like it, I stayed with a Tracker after learning all my first boat lessons on the PC 175. The 185 answered all my questions and then some.
Have fun with it. (Do I get advertising revenue for this message?)
Thad