So would anyone care to share their own thoughts on this? Am I making the Gold Box games too easy by modifying? Am I going to be endlessly frustrated trying to get good roles if I don't modify? What do you do?

I don't think I've ever played a Gold Box game without modifying my characters' stats (although I don't normally max everything), but based on what I've seen of the random generator it's pretty generous and gives well above average rolls. You certainly don't need high rolls to enjoy the game, but it does make it a bit more challenging without them. In Pool of Radiance, random encounter size/strength will increase depending on your party's combat ability (levels, HP, THAC0, and AC).

The most important thing is to make sure your multi-class characters can reach their maximum level cap, so they need high enough stats to do so.

If you're only considering Pool of Radiance, then note that there is a bug whereby multi-class characters do NOT gain bonus XP for high Prime Requisite scores, therefore:
Strength: Fighters should have max strength as it is very important in combat (and for non-human level limits). Even non-fighters will appreciate it because it also increases carrying capacity.
Intelligence: multi-class Magic-Users only need Int 10, single-class will want Int 16 for the Prime Requisite bonus.
Wisdom: Clerics should have Wis 17 to get maximum bonus spells
Dexterity: 15+ is important for all classes, you want this as high as possible for everyone (preferably 18)
Constitution: 15+ is also important for all (although it doesn't have to be higher than 16 for non-fighters)
Charisma: does have an effect on parlaying with monsters, if you're into that sort of thing. Only one character needs high charisma in this case.

(Also note that for PoR high party stats in Str/Dex/Con = increased size of random encounters = increased XP earned :).

In later games, Clerics will want WIS 18 to gain a bonus 4th-level spell, and Magic-Users will eventually need higher INT to gain access to high-level spells.

*NOTE: I haven't played the Krynn games in decades, the rules are subtly (or not-so-subtly) different so what I have said above may not apply 100% to them!

I use Reroll but not Modify. I think it a rather big design flaw that you have the option, but I instead choose to see it as an alternative way of adjusting the difficulty of the game than the actual difficulty setting, which simply just changes the monsters’ hit points, which is rather boring.

So if you just want an easier game, max all or some of their stats. If you want a challenge, stick to Reroll. This will give an entirely different gameplay experience even if you keep the difficulty level at Veteran.

The difference is rather dramatic. Like the famous rope guild encounter in Pool of Radiance. If you play with Rerolled characters it will be almost impossible to beat as a low level party, and you will need to return to it later. Presumably what the developers intended. But if you max all your stats, you may be able to breeze through the encounter and it will feel like one of the regular hobgoblin encounters for your Rerolled party. Anticlimactic to some, power fantasy to others.

Also keep in mind that if you not only max your starting stats, but also savescum to get better level up hit points, the difference becomes even crazier.

I recently completed the Krynn series with Rerolled characters and in the entire series there were only two battles where I had to reduce the difficulty setting to beat. They were some nasty draconian/dracolich/beholder encounters by the end of the third game. I haven’t played Pools of Darkness, but have heard some of the late encounters are really tough if you don’t have high Dex scores for initiative. But if true, you could always raise them once you get to that game. A bonus of the built-in difficulty setting is that you can always drop it for one particular encounter and then raise it again after.

AFAIK the reason for the Modify feature is so you could recreate your P&P character rather than to simply max out your stats. But you could use Modify to make an uber party that quickly ploughs through the games to experience the story. Though I would argue the combat is the games’ main point, as the engine isn’t built for intricate narrative and dialogue.

Ultimately it’s up to you and the experience you want. If you choose reroll, keep in mind there is a minimum you want for your character’s prime stat, depending on his class.
Oh, and if you are unsure if the games will be too tough, you could always start with Reroll. Then if it turns out too hard overall, use the Gold Box Companion to buff your stats and HP.

Personally, in the Gold Box games and FRUA modules, I roll one character for each alignment of both sexes and then choose the best ones to form my squad. This way I get decent characters, but not OP ones.
Also, each party will be different, and there will be some variation in "builds" (as in which characters end up dual classed).

For a very difficult mode, you could to six sets of characters using 4d6, drop lowest, assign as you wish. Then use Modify to recreate the results. Might end up with no characters with an 18. :p

I wouldn’t be looking forward to fighting draconians in the null magic zone with such a party, though!

Thank you for the replies.

I think what I am going to do is NOT modify their stats. It is probably going to feel too cheesy to me to do that. But I am going to save-scum on level ups for max HP. I am ok with doing that much.

I modify. 18(XX) Str, etc etc.

Why? More to the point...why not? I run with a tri-class F/MU/TH, so he needs all the XP help he can get, dividing every XP award between 3 classes. Higher party stats, = higher enemy count = higher XP.