I have had many different boats. Here is my take on two of them you listed:

Hobie 17SE - Had one for 3 years (circa 1988 model) and it was a great single handled boat. I would still be sailing one, but I have found them to be flimsy. I am a beach sailor, so the spring loaded boards looked like a great idea... but I have never known an H17 sailor that doesn't complain about them. I don't like how the wings are connected to the boat and quite frankly, that boat doesn't need wings. It was a fun boat though. Maybe the newer ones are built better... I had a lot of problems with mine.

Nacra 5.2 - This is a freaky little boat. We have the only active Nacra 5.2 fleet around so I know 10-15 guys with these things. I have a 1982 model. The bad points:
1. Not a lot of room... this is a two man boat max.
2. Not very forgiving.

Good Points:
1. Very powerful boat (good depending on who you are).
2. Cheap to buy and maintain. Parts are everywhere.
3. Built very solid.

It is a freaky boat. I think it is a riot and frequently solo without the jib. When I bought and re-did mine, we weighed it in the shop and it was under 300lb without the mast. Very light boat with 48" daggerboards and 220+sqft sail. Freaky is the only word to describe it. It is a challenge in gusty situation.