Hullo Redbythe sea. Welcome to the Forum, and to scroll sawing. Having been away from the forum for a while I've only just seen your post.
About 3 or 4 months ago I was facing exactly the same choice as you and after some tests I posted my own conclusions. I am definitely NOT an expert, especially not when compared to many of the members here, but my post in early June did seem to raise some interest and approval from members, so here's a link if you want to check it out:
biting-the-bullet-ex-21-t89722.html
As you'll see, in the end I opted for the Excali, and although it's not a 100% perfect tool (what is?), and I'm also sure that the Hegner would in many respects be just as good, I'm actually very pleased with my choice.
As many members here have commented in the past, when choosing any tool an awful lot depends on exactly what you want to do with it, and in my case, perhaps because lots of the stuff I do (so far) is a bit out of the general scroll sawing "arts & crafts main stream", for me the angled head (rather than the angled table) was a decisive factor for the Excali.
Also, I note that as in response to my own post, Scrimper has defended the blade changing characteristics of the Hegner here. During my own direct comparison of the two I found the Excali to be a bit easier/more immediately intuitive - not saying that the Hegner blade changing is bad, but I am saying that I simply found the Excali was a bit easier/quicker to pick up straight away than the Hegner was. But that's just me. As always," yer pays yer money and takes yer choice".
Again it probably depends on exactly what you want to do with your saw, but personally I've now found a foot switch to be an essential add-on. I had problems sourcing the "correct" switch for the Excali, but if you do go that route yourself a quick search here should pull up all the relevant details for the Excali because I posted all the info here.
Whatever your final choice it seems pretty clear to me that with either Hegner or Excali you won't go wrong, and as I'm sure you've already heard, you'll find scrolling both addictive and relaxing - just like something else I know
Again welcome, and good luck whatever you choose.
Hope the above and the link help.
Krgds
AES