Shipbuilding in ISW vs Spaceships

[Wonazer]

I know ISW came before Spaceships, ISW as a whole has a few issues that were later solved as 4e matured.

I only prefer Spaceships because I'm familiar with it, but I was worried that I'd break something. I worry too much.

Also, I'm not concerned about other editions of Traveller because I'm not familiar with any other Traveller setting, aside from what I've read in the last week. As is, I think I prefer ISW (over other Traveller time periods) since I was imagining a TL9-10 ish BSG inspired setting for my campaign. I was originally trying to shoehorn Star Wars into a TL9-10 GURPS existence-- it was ugly.

I'm put off by ISW shipbuilding complexity as well -- that's why I was asking about its output. Does it do anything better than Spaceships? If not, does using Spaceships break anything in ISW? Will I have to reimagine existing ISW ships? If not, I'll go with what I already know and run with Spaceships.