The boxset itself is just the regular German Infantry set with some metal addon parts (notably backpacks, gas masks - available seperately - , weapons, etc).
They different from regular infantry in that they come as Veteran as standard. However the only gain that the squad in the 2nd edition book have is that they can take a flamethrower. They get the same number of SMGs as a regular Heer Veteran squad, but lose out on the option for Panzerfausts.
There is a second squad of pioneers in the book however - Sturmpionieres. Again, they're the Veteran infantry profile. They maintain most of the Heer veteran options (which I'd mention neither pioneer squad get Assault Rifles), but get access to a Sturmpistole (repurposed flare launcher firing shapred charge rounds > read short range panzerfaust) and a dedicated grenade launcher (if you want grenade launchers the Battle of the Bulge book has Rifle Grenades > which were *much* more common).
The Goliath demolition vehicle is its own option. To be honest its not worth it as it only successfully explodes on something like a 6, which is pretty ridiculous (and well not reflection on the real world vehicle at all. Soviet bomb dogs are better...). Its a nice thing to have, and if you're going for a pioneer themed force maybe consider the many other demolition vehicles the Germans used - for instance the Borgward IV and NSU Springer (my own builds). Unfortunately the game only has rules for the Goliath and not the larger vehicles. Maybe they'll come along eventually.
Are they worth it? The Sturmpistole's just a crap panzerfaust, and well if you need to bring that and four of those things in one squad consider splitting your
AT up a bit. The Grenade launcher functions as a cross between a weak mortar/ panzerfaust - which for 30 points again maybe consider committing elsewhere. I suppose the main thing we're looking at then is the flamethrower. In Bolt Action those have limited shots, so you'd either use the squad to to taxi that to the enemy, or have it as a boost to the SMG fire in an assault.
Special mention would go to the upcoming Road to Berlin supplement if you're considering flamethrowers. The cover of that shops a Volksstrum armed with a late-war disposable flamethrower, so presumably the Germans will have access to cheap one shot flamethrowers if you want to add them at some point (presumably it will come sculpted to a metal model, but the thing could easily be made from a pile with a trigger attached and nozzle at the end. Woo, last ditch weapons).
As I said though, they're pretty much just Heer Veterans with some extra choices. If you don't go for the above you could get away with just using the regular infantry rules (or go ahead and use the
SS ones - they had plenty of engineers too).