Saleem,
With Enphase M215 inverters, you'll get-
1- 20% better performance. Each inverter takes the highest amount of electricity that is available from each panel. But a DC inverter can only pull power at the rate of the slowest panel. IE, if you have 3 panels putting out 190, 195, and 200 watts, the DC inverter will only pull 190 watts from each.
2- A 25 year guarantee vs 10 or 12 years on a DC inverter
3- Individual panel monitoring (Enphase), vs entire array monitoring (DC) (DC inverters essentially negate the 25 year panel warranty, since you never know if an individual panel is underperforming or not)
4- Much better performance if you have any shading issues
5- Safety for your family, as the Enphase inverters shut off the electric flow from the panels to the electric main panel when the breaker is shut off, not so DC inverters. If you have a house fire, the DC panel system is always hot with dangerous high voltage DC electricity.
Their price, at $3.73 per watt for a 7kw system, is pretty good. It's still higher than the comparable price from me in the bay area of California, $3.39 per watt for an Enphase system, but Connecticut is a hard place to get a deal
Watch out, cause they may try to add on charges, check for sure to see what exactly you get for the money that you put out. Cheap Chinese panels combined with a cheap Chinese inverter are commonplace for contractors who are only concerned with their bottom line, not yours. Make sure you know where they are running the conduit from the panels to the main panel, you don't want the conduit visible from the front of the house if possible. Many times, to save money, when they run the conduit down the roof, they'll run the conduit over your gutter, instead of through the roof and down the side of the house. Do not let them run the conduit over the gutter. And it's also commonplace for installers to put panels where it's easiest to install, instead of where you, the homeowner, will get the best performance. So make sure you understand the layout of the panels, and make sure that it's the best spot(s) for your production.