The hotchkis UCAs are really nice, and the anti-dive change is noticeable. But on a street car the heim joints are a pain in the butt. The first set of heims I had in my hotchkis UCA's only lasted 7k miles. Hotchkis replaced them for me at no charge, which was awesome, and included a set of boots for them too. But unfortunately I really don't see getting a whole lot more miles out of them, even with the boots. Heims just aren't a good solution on the street, and the UCA location is kind of like the trifecta for destroying them. The heims at the UCA's need a high amount of articulation, they're in constant motion while under a decent amount of load, and are in a spot where they are exposed to a lot of dirt and contamination. And the fixed front mount, while great for geometry, makes doing the alignment on the car a lot more tedious.
The Hotchkis arms are great from a design and geometry standpoint, and Hotchkis is a great company to deal with, but I'm not running heims on the UCA's on any more of my cars. For an adjustable strut rod or steering link it's a different story, but at the UCA location they just don't make sense on a street car. For a weekend driver or a race car I can see it, but not on anything that sees a lot of street miles. I use tubular UCA's with bushed ends on my other cars now.
The offset bushings should be enough to get a decent alignment on most cars. The tubular UCA's pretty much all have more caster built in, so for a power steering car they may be better as you can get even more positive caster, which is a great thing. On a manual steering car you probably don't want to go much more than +3 or +4 anyway. But in either case the offset bushings should be enough to get decent alignment numbers.
I wouldn't worry about the welds on the tubular UCA's as long as they're from a reputable manufacturer. The welds, when properly performed, should be just as strong as the surrounding material.
The only other advantage on a tubular UCA compared to the stock UCA's is rim clearance, but I don't think it's an issue on E-body's because of the backspace needed (or not needed, actually). On my Duster I needed to use a tubular UCA because my 18x9" rims would actually interfere with the stock UCA at full lock and suspension droop. Most of the tubular UCA's out there have a narrower profile, which adds clearance. But A-bodies need a lot more positive offset to run wide rims/tires up front. E-bodies basically use a zero offset rim, even going up to a 9" wide rim, so the clearance on the stock UCA isn't really an issue. It did come up when I had a "U" shaped tubular UCA, but most companies have gone away from that design for that reason, and most of the UCA's out there now are "V" shaped.
