Kelly I run larger bits than 3 inches. I build a lot of cabinet doors that are arched raised panels and the panel cutter with a back cutter is a 3 & 1/2 inch dia bit. I cut them all the time and have not altered the bottom of the router base. That is about the biggest bit that you would want to be running in a router table.
The thing about routers and router tables is that if you are going to use them on a router table you should dedicate the router to the table and not be removing it to use as a hand held one.
I do not know which triton you are interested in but if you expect to turn any bit that is bigger that what you can get inside the base plate opening you should be running the 3 &14 hp one (TRA001) as if you do not you will be under powered in anything that is harder that a soft wood. The TRA001 is a large router to be doing anything much as a hand held router as it is just simply too large and heavy. The smaller triton is a 2 & 1/4 hp router and much lighter and smaller so it makes a good hand held router as well as in a table providing that you do not plan on cutting with large bits and or using it in hard wood like hickory and some of the white and red oak.
The TRA001 is an excellent router for the table and has more that enought power to turn the larger bits and cut into the hardest of woods. In my 27 years I have owned and build several tables and used most of the brands out there including the popular bosh, poter cable, hitatchi, craftsman, freud, milwaukee and others and tto date I have yet to find one that works for me as well as the triton. It is like a small shaper with the usability of a router table.
It has excellent speed control and runs smooth under load or without a load. The collet holds well and allows easy bit removal and installation. The height adjustment of the bit system is hard to beat as you can use the below table adjustment with fine tune of the bit or you can use the handy through the table by crank giving you accuracy and speed. This covers two of the major factors that should be considered when choosing a router to use in a table. How hard is the changing of the bits and how hard is it to adjust the height.
Many do not think about a router and how it is built as they are aquainted mostly with the hand held method as when mounted into a table it becomes a different ball game. One advantage of the triton is that the air flow through the motor is from the top towards the bottom making it an ideal router for table use as it does not suck as much dust and wood chips throught the motor. Most routers do just the opposite resulting in a lot of dust in the motor in a short time of use on a table.
As I said I have many years of experience with a router table and with many brands of routers. if I had to do it again my first choice would be the triton.
Check out my router table that I recently built. It has a triton in it. I also have a slide show on making raised panel doors that will give you an idea as to what the triton will do for you.
Any additional questions please feel free to contact me. Welcome to the exciting world of woodworking and I hope you will experience some good times during your venture. Take care.