blkmonday:
Welcome to TFP
From a cost standpoint, considering that you already have a salt water chlorine generator (SWCG or SWG), it will likely cost you less to continue using it as opposed to manually dosing the pool. If you
did not already have the SWCG, the cost between it and manually dosing your pool over the long haul would be awash since you would be looking at the up-front cost of installing the system.
The main advantage of a SWCG is convenience. If you frequently travel and the pool is left unattended for more that a few days at a time, the SWCG will keep the pool properly chlorinated, assuming it is calibrated and working properly. You do not have to haul and store bleach/liquid chlorine bottles (the preferred chlorine source for manually chlorinated pools) nor do you need to find someone to look after your pool while you are away. Another advantage of SWCG is that they are designed to produce small amounts of chlorine continuously which allows you to use slightly lower FC levels compared to adding chlorine manually.
The disadvantages of SWCG is that you will likely need to replace the salt cells every 3-5 years on average and test / adjust the salt ppm periodically. In addition, you need to test / adjust the percentage setting that controls how much chlorine is produced by the SWCG. Since the setting is a percentage of the pump run time, you will need to readjust the percentage if you change the pump run time. During periods of high chlorine demand, you may need to increase the pump run time to be able to produce enough chlorine. Some of this effort is offset by not having to manually dose with chlorine daily or several times a week during swim season. Finally, SWCG do not work very well at producing chlorine when water temps get below 60°F, so you may need to supplement with bleach/liquid chlorine. However, since you are in CT, you probably close your pool for the season so that may not be a big concern for you.
The advantages of manually chlorinated pools (aside from the lower up-front costs vs. a SWCG that does not apply in your situation) is that you do not have to worry about replacing salt cells every 3-5 years, plus there is no equipment to periodically calibrate and maintain.
The disadvantages of manually chlorinated pools is that you (or someone) will need to manually dose the pool to maintain the proper FC level. You also need to regularly purchase, haul, and store bleach / liquid chlorine bottles. If your pool is frequently left unattended for more than a few days, you will either need to find someone to dose your pool while you are away or temporarily use trichlor pucks which if used too often will increase CYA.