Question about 4E tech books

Hey all! I am new to the forum, but certainly not new to GURPS! I have played GURPS since I begged for (and received) the 1st edition box set for Christmas. Third edition was the last edition I played and didn't have a lot of interest in trying 4E. Recently though, I have been picking up some 4E books and that brings me to this question.







I'm specifically wondering about the tech books. I have just bought the 4E ultra-tech from someone online, but haven't received it yet. If I have the 3E low-tech and high-tech books... Do I really need the 4E books as well? I've seen pdf scans of the 4E low tech book and most of the damage and speed stats seem to match up with my 3E book (even the prices are the same). I have seen many people mention that the 4E high-tech book differs significantly though.





So, I'm basically hoping people that have familiarity with both editions can tell me...



1. Whether I need to buy both 4E low and high-tech books

2. If I just need to buy the 4E high-tech book

3. Or if there really aren't any major differences and I can make do with

the 3E books





With the High-tech book seemingly hard to find (and very expensive when I do find it), I'm hoping I can make do with the old version. If I have to update though... Well, I'll have to bit the bullet and spend the money. Thanks for reading this and I hope to hear from GURPS fans everywhere!

Question about 4E tech books