I'm a long time EJ89 fan and I've too often been tempted to try new razors, and spent a fortune, only to arrive at the conclusion that the EJ89 is still the best (for me at least). But, reading through this thread, here's my minor contribution:
An adjustable might seem like a good idea, but you might still find that none of the settings works for you. The Progress looks like one of the more affordable ones unless you want one with a customised adjustment knob. Unfortunately the Digress with the cool brass/chrome/steel adjustment fitting is no longer available...I asked Ian in Scotland who was selling them and he told me only a few weeks ago that he'd had none for ages and the guy who made them seems to have stopped.
I found most of the Merkur range pretty good, but been disappointed with most of the other razors I've tried, compared to the EJ89. Then, instead of wanting lots of new razors, I decided instead to look at different handles...it's amazing how much difference a handle weight, length, knurling, etc can have on the same razor head. So now, I have a few EJ89 heads and a bunch of different handles. Trying out different blades with the same razor head also provides lots of variety.
I do occasionally try different razors...I had a go with the Razorock Hawk V2 recently...didn't really get on with it. Then I went back to my EJ89 and wondered why I ever wanted to try anything else!
Final comment: The EJ89 is often reviewed as the ideal razor for wet shave beginners, and this sometimes creates the impression among wet shave beginners that it isn't a razor for the truly experienced wet shaving 'veteran'. This is of course nonsense, and I would guess that most people in this forum would consider it an almost legendary razor that's so good even a beginner can't go wrong with it. I suppose it's worth looking for something else if you really want a challenge, but I'd suggest testing out variations on the EJ89 with blades and maybe handles first to establish a benchmark setup to judge other razors by later.