I have not played either, however there is a thread on RPG.net that discusses many of the same things: The RPG.NET thread on the topic

However, on reading it only the first comment is useful to you, so I am going to quote the relevant parts here:

Troubleshooters is the 25th Anniversary edition of the Mongoose 2004 PARANOIA rulebook (formerly known as XP). There are minor tweaks to the rules, but it is basically the same game. Likewise, the companion Internal Security rulebook uses the same system, though there is extensive new material there for BLUE-Clearance IntSec missions. Neither is mechanically complex, and both place unique emphasis on the Gamemaster's supremacy. Every rule in both books exists as a non-mandatory advisory to the GM's incontrovertible authority.

In contrast, High Programmers is a completely different game with an unusual and innovative rules system. It isn't necessarily complex, but the players have more options and hence a greater cognitive load than in Troubleshooters or IntSec.

Each book offers copious advice on designing missions, plus pregenerated player characters. Troubleshooters, in particular, adapts the XP GM Screen's "mission blender," a collection of tables that lets you generate an entire mission randomly with the roll of a mere five dozen or so d20s. Troubleshooters also includes Ken Rolston's classic introductory PARANOIA mission "Robot Imana-665-C" as well as a fine new mission by Gareth Hanrahan, "The Quantum Traitor." High Programmers includes one mission, "Disaster Management."

— Allen Varney, 04-16-2010

Other comments in that thread indicate that the Official Paranoia Development Blog has information on the designers goals with each system.

I hope this helps, it seemed a shame to have this thread with no answers for so long.

I have not played either, however there is a thread on RPG.net that discusses many of the same things: The RPG.NET thread on the topic

I've quoted some relevant parts below:

"Troubleshooters is the 25th Anniversary edition of the Mongoose 2004 PARANOIA rulebook (formerly known as XP). There are minor tweaks to the rules, but it is basically the same game. Likewise, the companion Internal Security rulebook uses the same system, though there is extensive new material there for BLUE-Clearance IntSec missions. Neither is mechanically complex, and both place unique emphasis on the Gamemaster's supremacy. Every rule in both books exists as a non-mandatory advisory to the GM's incontrovertible authority.

[...]

Troubleshooters, in particular, adapts the XP GM Screen's "mission blender," a collection of tables that lets you generate an entire mission randomly with the roll of a mere five dozen or so d20s. Troubleshooters also includes Ken Rolston's classic introductory PARANOIA mission "Robot Imana-665-C" as well as a fine new mission by Gareth Hanrahan, "The Quantum Traitor."

---Allen Varney, 04-16-2010

"If you have Paranoia XP, you can play Paranoia: Troubleshooters - the mechanics and content are 90% identical. The only substantial difference is that Troubleshooters returns to the old Treason Point system, with the more complex "Treason Damage" mechanics reserved for Straight games.

[...]

As for rules for mission structure, Troubleshooters is pretty much the same as XP, apart from some expanded GM advice and some fun tables for randomly mission generation (which sometimes even produce sensible results). "

---David J Prokopetz

Other comments made in the thread indicate that the official development blog has many insights into the changes.