As Tim pointed out, you will be losing about #110 pounds per tire by downsizing from a 215 to a 205, and lose about 0.3 inches in total tire diameter (according to Carlisle tire specs sheets on Diagonal/Bias tires). This weight loss translates to #220 pounds total loss in trailer carrying capacity.
There was a good discussion on this concerning the 2720 a few years back, and you can find it at this link.
http://www.trailmanorowners.com/foru...?t=6750&page=3
Personally, I wouldn't recommend the downsize, as we have been saying for a long time that the trailers are overloaded on the six ply rated 14 inch tires......which is why so many members are upsizing to 15 inch rim diameter tires or at least using eight ply rated 14 inch rim diameter Euro tires.(which you might also want to consider before going back with a 215/75?14 six ply rated tire)