The Perry Class did not replace the Spruance. They were contemporary. The Perry Class (long hull and short hull) were Frigates. They were referred to as missile sumps due to their minimal defense. The Spruance were "destroyers." Though they shared the hull of the Ticonderoga Class cruisers, they were designated destroyers to get them through congressional military allocations (which had said "no more cruisers.").
The Spruance/Ticonderoga Class kits (along with the Kidd Class - known as the Ayatollah Class) whether DML or Dragon or whatever, are VERY difficult and problematic due to their poor fit.
The Academy Perry Class, on the other hand, is highly recommended and builds well. Add a photoetch accessory such as from White Ensign Models, and ti builds into a real winner.