Both are legendary optics for good reason. I say go for it. If you are curious, then just take the plunge. It'll sort itself out. After a few years, you'll probably get curious about another pair of binoculars, at which time I will also recommend that you go for it. Get a good price selling your Ultravids and a good price buying your ELs, and worry no longer.
I've bought a lot of pairs of binoculars over the years. I've owned a pair of EL 10x42s, but sold them. I currently own a couple pairs of Ultravids and a couple pairs of Trinovids. I'm a 42 user. And a Leica fan. But it's taken some experimentation to learn my preferences.
I've bought a lot of pairs of binoculars over the years. I've owned a pair of EL 10x42s, but sold them. I currently own a couple pairs of Ultravids and a couple pairs of Trinovids. I'm a 42 user. And a Leica fan. But it's taken some experimentation to learn my preferences.