Yes, the Hotchkis design has a lot of merit to its layout. If you like to corner fast or drive hard, they will make a difference. Where their layout really shines is at the higher end of suspension travel. It is at these levels that they demonstrate more consistent, predicatable performance that will require less steering wheel effort to keep things pointed in the right direction. A regularly mounted tubular arm just won't show the same benefit.
If you simply cruise your car to the local show and shine and and baby it there and back to avoid rock chips, you may never push it hard enough to see a benefit. If you want increased alignment capability to provide the biggest benefit in handling for the least amount of cost, offset upper arm bushings may be the ticket.
If you're somewhere between these two extremes, there may be some benefit, but the more causal you drive, the less noticeable the changess will be while pushing things hard will demonstrate more benefit.
The angled mounting that is part of the stock mount is anti-dive geometry. Back in the day when ride rates were noodle soft, adding anti-dive to the front suspension prevent the nose from doing a swan dive when the brakes were applied. Yes, they still dive some with this anti-dive built in, but it is much less than would be for a flat layout. Race vehicles typically sacrifice the anti-dive for more linear travel because the increased spring and shock rates are enough to resist the nose-dive motion. You can increase anti-dive more to provide further resistance, but doing so creates more radical angles in the dynamic geometry and increases the potential for binding a component.
