If you hunt a lot in hot weather - Guido's won't work. Definitely, I won't use mine until its below 60 degrees. It's soft saddle until then.
If you intend to pack a lot of weight - the guido's isn't really suited for it. Agreed, I would not use the Guido like a frame pack. However, I can fit up to 12 WE stepps (usually carry 8), water bottle, small fanny pack, and extra clothing inbetween the back and seat when folded up. I would not pack out meat with it.
If you want to climb with the seat folded up behind you while maintaining functional lineman's belt - the guido's won't work. Yep, if you don't like the seat down when climbing, definitely go with the JX3. I did find the Guido's lineman loops much easier to access with heavy clothing. The JX3's sit back on your hips.
If you want an adjustable fork - you'll have to modify the guido's, or you won't have it. Yep, the adjustability was great on the JX3. The fork on my Medium Guido was just about perfect length, it's a little long on the Large. I always ended up keeping the JX3's fork all the way in.
Essentially, if you want the above features, you need a JX3. If you can tolerate not having them, and want to save some dough in the process, get a guido's. It was the first saddle I owned, and I loved it. Until I met the JX3. I kept my Guido's until I got a full season on the hybrid (as a backup).
I have since sold the guido's and have a second hybrid. Sentiments aside, I don't miss the web.
But your budget is your budget. Get what suits you.