Been using a ZSA Voyager as a travel keyboard for work and very satisfied with it. Used a Sofle V2 prior to that but I was concerned about how well it was (or rather wasn’t) holding up to the rigors of travel so I replaced it with something designed for travel and a little more robustly constructed.
I use a Workman layout and a few years ago switched to using homerow mods so I found the modifier keys on the Sofle to be redundant so I decided to downscale to something a little more compact. Because my usage is for work the number keys get used heavily so I wasn’t willing to give those up by going to something like a Corne. On the flip side I wouldn’t use the Voyager for gaming due to those same missing modifier keys since keys like shift and ctrl are used in a non-modifier pattern when gaming.
It’s usually more an issue of technique than it is the tools. Does your iron have adjustable heat settings (they usually do)? Make sure you have that high enough. Additionally you need to hold the iron to the pads long enough for them to heat up and have the solder bond to them. If the pads aren’t hot enough even if the solder melts it won’t flow over the pad and make a good connection. Using flux is a must. Flux helps remove the layer of oxide and any foreign contaminants from the contacts allowing the solder to flow and bond easily as well.
The easiest way to tell if the pad is hot enough is the solder will flow across it instead of staying balled up.