I replaced a 19" CRT monitor with a 17" LCD several months ago. The viewing area is roughly the same. Native resolution on it is 1280 x 1024. (Native resolution: The resolution LCD's look best at due to how they work)
After getting bitten by the Linux bug, I purchased a 19" LCD so I could use the 17" LCD on the computer I set up for Linux. The native resolution of the 19" LCD is also 1280 x 1024, the biggest difference is that everything is a bit larger.
The biggest size differences will be determined by the resolution you run your current CRT monitor vs. the native resolution of the LCD. If you run the resolution of your current monitor at less than 1280 x 1024, then, yes the text will be smaller on the LCD. If you run your current resolution at close to 1280 x 1024, you most likely will not notice much difference (or any difference will be quickly forgotten).
Naturally the biggest advantage is that everything is proportionally larger on the 19" (at the same 1280 x 1024 native resolution), which is a big help to these eyes that are not getting younger.
A disadvantage I've noticed is some games (mostly board type) don't look as good as some want to run at a non-native resolution so the 'jaggies' are enlarged on the 19" LCD.
I don't play fast action FPS or RPG type games, so one of the (mostly older) disadvantages of LCD's don't apply - smearing on fast moving scenes. THG has some pretty good reviews and enlightenment on this. You have to set your priorities with what you want in relation to your budget. Keep in mind, too, that not all monitors have the same 'viewability' from looking from the sides. This could be important if you need to see what's going on from off center.
Price-wise, I went to one of our local US emporiums (Best Buy) prepared to buy another 17" monitor until I saw the 19" one for $30 more ($279 vs. $249). Both monitors are Westinghouse & both satisfy my needs. I had perused New Egg, but at that time, did not find anything I thought I could get past my wife that I thought I would be happy with. . .
If you go shopping at your local emporium, don't base your decisions soley on what you see on the "wall of monitors" running the same "programming". They use distribution systems that I've found to be inconsistant from monitor to monitor. My way around this is purely bogus: I pull up the OSD & look at it!! As I said, it's a bogus test, but if I have problems with reading the OSD menu, I know the cruddy picture may be more than a flakey input signal.
As an aside: If you use Windows, download the Clear Type power toy to tweak how Windows handles your text fonts.
I hope your eyes have not glazed over with this!! It's just my 2 cents.