I have a 1997 Coachmen 220RK Catalina series, and it's been a problem free MH since I bought it in 2008. Of course that has no bearing on a "newer?" Leprechaun series. Over the years I think it's safe to say that Coachmen (now a Forest River Company) has put out a decent quality MH. Like anything else, you can get a "good one", while someone else with the same model can get a "not so good one", or vice versa.
As far as floorplans, I don't think there are very many unique to one manufacturer. If someone does come out with something a little different, which proves to be popular, the other manufacturers will copy it soon enough.
The only "unique" floorplan I can think of in my limited experience is the Nexus 25P which gives a full wall slide with a walk around Queen size bed, in a unit that's under 25'.
2014 Itasca Spirit 31K Class C
2016 Mazda CX5 on Acme tow dolly- 4 trips ~ 5,800 mi
Now 2017 RWD F150 with a drive shaft disconnect