I didn't build Mirage subs, but I built the 1/400 V106 World War 1 torpedo boat. It went togeather well, was easy to add photoetch to and was small enough to model "in water" ; actually painted acrylic gel. If you buy photoetch there are ones made just for those models. I found the railings awful to work with and ended up using spare Tom's model works railing. The problem with the Mirage railing was that each stanchon (the verticle part that stands up) was an individual wire, no rim around the base if you will. It made super glueing it to the hull a night mare (for me anyway), globs all over, so I ripped it out and put Tom's in.
Other than that it was a great kit. Got lucky and managed to get an honorable mention (4th ?) at the spring Seattle IPMS show, so if anything was wrong it wasen't the kit by Mirage; just me.
If the sub is as good as the boat it's a nice kit for the money. Get the P.E. too.
Have fun..............
G.L.