Originally Posted by rm -rf

Which bike is more comfortable on long rides? I'd take that one.

Get a lower gear
Some local riders have converted from a 27 or 28 tooth low gear to a 32 or 34 low gear. (And these low gears are getting more common on new bikes, too.)

The lower gears have really helped them on group rides. They can climb hills better without maxing out their effort.

It needs a new cassette, and usually a new mountain bike derailleur, or a longer arm on your derailleur, but those aren't too expensive. Check with your local bike store to see if they've done those conversions. The mountain derailleur conversion works differently on 11-speed, I think, due to different cable pulls between shifts on 11-speed.

Low gear differences:
Since you won't change the chainrings, just compare the percentage differences between cogs.
New low / Old low.
30/28 = 1.07, is 7% easier
32/28 = 1.14, is 14%
34/28 = 1.21, is 21%

1:1 low
A 34 cog on the back and your 34 chainring is a 1:1 ratio, really nice on hills. I have a 30 front and 29 rear on one of my bikes, which is essentially the same thing. I can sit down on 10% grades, going at a very slow speed, with just moderate force on the pedals. With a 28 low, I'd be standing up and pushing pretty hard on the pedals--faster, but hard to maintain for too long.

I'll even use my lowest gear on a much less steep hill, so I can keep the cadence high. I like it.
(My other bike has closer gear spacing, for faster riding on flatter terrain.)

Percentage changes per shift to compare:
Rear shifts range from around 6% to about 15%, depending on the two cog's tooth counts.

So, compared to a 28 low, a 32 cog will be about 1 1/2 shifts easier, and a 34 cog about 2 to 2 1/2 shifts easier. That's very helpful.

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Bigger gaps between shifts
The tradeoff on these wide range cassettes, like a 11-32 or 11-34, is larger jumps in cadence in the middle gears.

Here's a chart, at typical flat road cadences, for the 11-28, and below it, 11-32. The 50 chainring is in black, and the 34 in red.
You can see bigger gaps between shifts on the 11-32, but it's not bad at all. Worth it if there's a lot of climbing to do.

It kind of depends what typical speeds you ride. In some speed ranges, the two different cassettes both have reasonable gaps between shifts.