Simply led the GI's. Lower investment, biggest return.

Have you been able to find the amperage of any of these leds?

Even gi is more than 50 bulbs.

I did some power monitoring on some of my pinball machines, both incandescent lamps and LED lamps. See here:

https://pinside.com/pinball/forum/topic/power-monitoring-on-various-pinball-machines#post-3943326

I can change Wikipedia to state a different figure if that would help......

I doubt there would be a huge different with ambient heat in the room with a small number of games. With a larger number of games, there might be a small difference. The thing is that bulbs aren't the only components generating heat. The size of the room would also be a factor.

The main benefit is reducing the heat inside the game to prevent plastics, inserts, and backglasses from succumbing to damage (warping, flaking, and burning), and reducing the amperage draw, which helps prevent burn damage on circuits and wiring (especially in WPC games).

1SMD/4SMD bulbs from comet are $0.69 each, $16.25 for 25 ($0.65/ea), and $59 for 100 ($0.59)

OP, what was your final decision: to LED or not to LED?

I prefer the look of incandescents. So, I have switched all of the 44 bulbs to 47s and all the 555's to 159's to cut down on the heat. The 47's and 159's are supposed to be a little dimmer, but they are completely fine for me.

I not long ago started the process of un LEDing all games.

I'll take pleasing to the eyes over a worrying about a little heat anyday.

They really don't all have to be on at the same time anyway.

Why is it that the incandescent bulbs that blow the most frequent are the ones in the tightest, most inconvenient spots to access?

That's known as "Tesla Murphy's" law.

Wow, do you keep all 60 of your games on at the same time? Then yes, that's a huge power draw.

I have 14 games, they are all incandescent, but I only have 1 or 2 on at the same time. I use 47 instead of 44 bulbs and 159 bulbs instead of 555. These are lower power, so they have much less heat. Granted, they are slightly dimmer, but it never bothered me...

If we had the LEDs of today back in the day it would have been a no brainier for us at Bally. Incandescent bulbs use a boatload of power. They were the single largest drain on power and required heavy transformers and beefier connectors that wouldn't burn. There is also the damage and wear to the playfield rubber and plastics as well as the backglass art the heat of the bulbs caused.
LEDs draw a fraction of the power with less heat and give off much better light that can be colored for effect. You have to do it right but I'm all in favor of LED converting older games.

Just don't join the Rainbow Puke club!

I have yet to whole change a playfield's lighting to LED's but heads are a almost must have at this point, due to the heat issue as you noted. The first one I'm likely to do is Eight Ball Deluxe, even just having that game on for a party after about an hour of it being on the playfield glass is noticeably warmer than other games. I can't handle the flickering so before I do it I'll have to get one of the truly flicker-free solutions or I get a huge headache.

I'm working with older games (Duotron and Domino) and have opted for LED in the head and under the playfield, and incandescent above deck. I just like the way they look; I've sought games I might have encountered as a kid in what is clearly a nostalgia buzz, and LED lamps above deck takes away a bit of the magic.

I imagine the more modern games which have a ton of bulbs under the playfield ratchet up the heat AND the cost of transitioning to relamp. I think I've got a lifetime supply of both incandescent and LED lamps hanging around.

One benefit was using red LEDs under the special and bonus inserts - Duotron's were pretty faded (much more so that the green inserts on the game) so with incandescent or LED bulbs, those lamps were more pink than red. The red LED bulbs really made the red inserts really pop without having to replace or augment the insert.

Incandescent = heater that produces light as a byproduct.
Led = light that produces heat as a byproduct

The choice is simple. IMHO