I think the tip and the grip are both very important. Finding a good grip that you want to use every day is pretty important regardless of the tip, companies with the same good tip can offer a crazy wide selection of different handles, so definitely a worthwhile question and personal preference. As an example, I am for sure not a fan of the vessel composite wood hard handle, others love them. People with arthritis, really like the vessel ball groups as an example and I like them.
The top three you have listed all have very good tips.
If you want to see a comparison and handle shape and scale of the three grips from companies you mentioned, here's a comparison pic below of a Phillips #1 of the three. The vessel grip looks big in the picture but in reality it is not and size wise feels good in the hand, the 75mm long shaft is a good length for that grip/
I agree with others to sample one driver of a handle that you’re interested in before buying a set. The screwdriver set is probably the number one most used tool in your shop, so it’s worthwhile to invest in finding the right grip that you like to use. On the ones I'm not liking, I've been giving the drivers as gifts to friends and clients to try.
I’m pretty much now only using European hollow ground slotted tips for all my fasteners including on American imperial sizes using PB Swiss or Felo Long shaft bits using them with a modified Vessel bit ball grip handle with a set screw that locks the bit in with zero play/slop, they’ve been working very well on Starrett slotted fasteners and other expensive american made machines. Hollow ground slotted tips usually come in two different thicknesses. Felo has a full selection of tip sizes to choose from and not expensive and key to having the right size. It also gives you a hex bolster and cheap to replace if worn. I’m getting away from the slotted wedge shaped drivers, they're hard on fasteners.
Sorry, I have digressed and veered well away from the subject of soft handles. Good luck and hope this info is useful. I'll update after tomorrow when I sample the Megadora's
EDIT:
FYI: The PB Swiss soft grips have been a pain to clean, they easily show black grease marks that are really hard to get out as noted by many others. Yesterday I went full monty on the set, using Goof Off Gel adhesive remover and then putting them in a ultrasonic cleaner, it worked well (as seen in pic) but can still see some grease stain marks in the pores on my larger drivers and not sure how often I can get away doing that but they do look much cleaner. Probably wont do it again.
