Do you favor one of these over the other? For example, which would you prefer to use for a large endgrain bowl (a la Sally Burnett’s)? I’ve been going back and forth between these two, and eventually will purchase one.
Michael, I pay little attention to the pros and cons of end grain etc, rather blank orientation, so I can get the very best out of it for what I have planned for it. So whatever issue the grain my throw up, I just deal with it on the day.
As for hollowers each one has its good points, basically the Pro-Forme will remove wood like no other especially on green blanks where it can be opened up to produce a chip 1.5mm thick while using the full length of the tool. The Wunderkut works best at Rolly's recommended setting of .25mm, and at this setting it will clear its self. Once you have mastered either of these hollowers both are very capably or roughing and finishing cuts and the WunderKut tends to lend its self to smaller vessels as the head is smaller. It is a bit fiddly to adjust, so I leave at the .25mm preferring instead to adjust the Pro-Forme. Sharpening, the Pro-Forme for me is easier to sharpen than the WunderKut which have to virtually strip it down completely and the process of setting the .25mm is not as quick
Which one is best or use the most? I use both all the time on most pieces. So I think it would depend on what you're turning. If you're making small pieces, much like our swap. Then the WunderKut with smaller articulated head would be the one I would go for. On the other hand, if you turn larger pieces with some depth, the heavier bent bar of the Pro-Forme would lend its self better. As a point of interest, my Pro-Forme has a 3/4" bar and the other 16mm or 5/8th and they both work well even with the Aussie hardwood.
The learning curve of the Pro-Forme can be slow for some in finding the sweep spot, and it has a tendency to self feed on heavy cuts with green wet wood. But is readily controlled by simply rolling it over into the cut, whereas the WunderKut is more straight forward, rolling is the simple control method used on both.
I understand about going back and forth, I did the same and ended buying both and do not regret either purchase. As a matter of interest, Woodcut will sell you the head only, and you make the rest the saving is around 60% and its not hard. If think you may want to go this way, PM me and I will put something together, either that or we can catch up online and speak about it.