I ordered one of their Unit 1 (http://www.marvelprod.com/beauty.htm) conversion kits earlier today. I ordered a commander-length kit with both open sights / scope-mount rail and a threaded barrel. But the lady I spoke to couldn't tell me ANYTHING about the accuracy of the 4.25" conversion kits compared to the 5" kit; except that the 4.25" kit is tested for accuracy at 25yds and the 5" is tested at 50yds. She said they have NEVER tested the 4.25" at 50yds or the 5" at 25yds. Doesn't that sound a little weird? I got the 4.25" conversion because I only have commander-length and shorter 1911's and I wanted to be able to train with the open sights and target shoot with the scope rib. But now I'm second-guessing myself, and wondering if the accuracy of the 4.25" barrel is going to suck compared to the 5" barrel (which I hear is awesome). Anybody care to comment on the accuracy of the Marvel Unit 1 conversion kits in either length? They're backordered by about 6 weeks, so I've got time to change my mind.

From their website:
...each Marvel .22 Rimfire Conversion Unit is shipped with its own test target that is less than 1" - sometimes MUCH less - for 5 shots at 50 yards from a Ransom Rest.
....Unit 1 Commanders are ransom rest tested at 25 yards. It is a 5 shot group, and the accuracy will be under 1” at 25 yards.

link to their target page (http://www.marvelprod.com/testtargets.htm)