As someone who has taken classes from both agencies, I think you'll get very similar training from either. There are small differences in procedure and gear configuration, but nothing that precludes people trained by one agency from successfully diving with people trained by the other. (And this is commonly done in lots of places.)
UTD Essentials and the GUE Primer are non-certification classes that introduce DIR gear configuration and basic skills. Intro to Tech and Fundies for a tech pass are similar, except UTD ITT introduces bottle-handling skills. I think they do this because they're kind of assuming Essentials or similar training or experience, whereas Fundies has been the entry level class for GUE for a long time, until the recent development of the Primer.
Where it gets more different is at the Tech level. GUE jumps from Fundies to Tech 1 (150 ft, 21/35 and 50%, up to 30 minutes of deco). UTD goes to their Tech 1, which is a 25/25, 130 foot class with O2 deco up to 15 minutes. It's a little less stressful class, designed for folks who don't really want to do deep dives, but would like to do some deeper recreational dives properly planned with staged decompression. I took it, and it was a good decision for me, especially as I have repeatedly struggled with GUE classes the first time through.
I should mention that UTD teaches almost exclusively Ratio Deco, whereas GUE uses DecoPlanner with multiple kludges, and RD as a backup.
Given that location isn't a big issue for you, and you're not trying to stay consistent with a team or community of other divers, I think you should find an instructor you click with and do whichever class they teach.
UTD Essentials and the GUE Primer are non-certification classes that introduce DIR gear configuration and basic skills. Intro to Tech and Fundies for a tech pass are similar, except UTD ITT introduces bottle-handling skills. I think they do this because they're kind of assuming Essentials or similar training or experience, whereas Fundies has been the entry level class for GUE for a long time, until the recent development of the Primer.
Where it gets more different is at the Tech level. GUE jumps from Fundies to Tech 1 (150 ft, 21/35 and 50%, up to 30 minutes of deco). UTD goes to their Tech 1, which is a 25/25, 130 foot class with O2 deco up to 15 minutes. It's a little less stressful class, designed for folks who don't really want to do deep dives, but would like to do some deeper recreational dives properly planned with staged decompression. I took it, and it was a good decision for me, especially as I have repeatedly struggled with GUE classes the first time through.
I should mention that UTD teaches almost exclusively Ratio Deco, whereas GUE uses DecoPlanner with multiple kludges, and RD as a backup.
Given that location isn't a big issue for you, and you're not trying to stay consistent with a team or community of other divers, I think you should find an instructor you click with and do whichever class they teach.