Whether a faster charger is better depends on its method and accuracy in measuring charge state and terminating the faster (if not only) charging mode, then if any, what the lower aka trickle charge mode does too.
The specs not on the labels are more important, for example whether either is a Delta -V terminating charger and if so, does it then trickle charge indefinitely or time-out after some period. If it does not time out then it will cook the cells slowly. Sometimes the specs can just be "up to" numbers, that don't really indicate what they're doing at any particular point in charging any particular cell capacity. Probably semi-close and possibly comparable between two models from same brand, but how close they stick to the #s depends on how they are regulated and the charge scheme used, whether constant current.
If neither is Delta -V terminating, they might use a timer circuit then overcharge or undercharge the cells depending on the charge state when inserted and their rated (vs real remaining) capacity. I doubt either lack both the Delta -V and a timer shutdown feature, because that would make them terrible, but it's not impossible.
It is gentler on batteries to charge them slower, but for the most reliable Delta -V voltage detection, the charge rate must be above a certain % of their capacity. That can vary by cell design but a rough ballpark is around 25% of the capacity so for a 2000mAh rated cell, 500mAh charge rate, BUT, depending on the charger design, it may put less current through a battery with a higher internal resistance.
If you have more specs that might help, or otherwise the thing to do is measure what they're doing. If they lack an LCD display or provide inadequate info on it, the way to do that is insert a double sided thin piece of copper clad PCB material (in series with the battery contact against the charger contact), with multimeter probe connectors soldered to both sides, so you can measure with a multimeter during the process, what the current is doing, except in order to measure the current the meter will insert a little more resistance to pull the #'s down a bit.
Even if they are using Delta -V, that does not guarantee they work well to fully charge the cells. Many cheap chargers do poorly at this, stopping rapid charge closer to 90% capacity but displaying a "done" green LED or whatever.
It's really easy to state "get a better charger", but in the long run that may be the best route to take if you start using rechargeable batteries a lot, especially if you'd like to run some LED flashlights that take 18650 cells, to get a full featured charger capable of Li-Ion in addition to NiMH.
On a related note, a couple of good forum resources for chargers are
https://budgetlightforum.com/forum/batteries/chargers &
https://www.candlepowerforums.com/vb/forumdisplay.php?9-Flashlight-Electronics-Batteries-Included
As far as using what you have, the only way to know for sure is measure, log what they're doing, graph it and compare, but Delta -V is the big one, most important feature if you don't want to babysit and check voltage every single time you charge.
Sometimes, more often with a major brand (generics may scrub the IC markings off their counterfeit chips), you can open them and identify the charge controller IC then look up its feature set on the datasheet.