Did they have the same or similar uniforms, or were they substantially different?

East German uniforms retained many Wehrmacht features. If you do a Google image search for each Warsaw Pact army, you'll find a wealth of photos.

There's an Osprey Elite series on it: Uniforms of the Warsaw Pact.

Only so many things one can do with a tunic and trousers. Post 1970 Soviet troops match many of the other Warsaw Pact uniforms with small differences in pockets and camouflage patterns. Some countries though wore the same uniforms like Poland and East Germany. Insignia and equipment and helmets were different the "rain pattern" field uniform was nearly identical.

I used the ancient Dragon Spetnaz set to make Polish infantry back in the day. Fairly easy since I had a full 1/1 uniform to work from back then. Sold it all off at a garage sale to add kits to the stash.