After shooting my 41 Magnum Ruger Blackhawk a few times, I decided that it could use an optic to shoot it more accurately, since I'm not that good with open sights. Earlier this year, Whitworth mentioned that Weigand offers a no-drill mini mount designed for small reflex style red dot. I've considered an Ultradot L/T and Leupold Deltapoint, and my local store had a Vortex Venom that looked pretty nice.

What sight would you recommend?

I have several Burris Fastfire 3 units on a few different guns. None have ever given me a bit of trouble. The one on my SBHH 44 was dropped (with the gun) and never lost zero, despite bending the aluminum frame of the sight a bit. I am quite pleased with the Fastfire 3.
As a side note, the Weigand mini mount you mentioned just arrived at my house to go on a Blackhawk 357. I haven't installed the mount yet, but it will wear a FF3 when I get time to put it all together.

I'm quite interested in that particular mount ... do let us know your thoughts on how solid it is.

I've been using both that mount and the Ultradot L/T for some time now on a .45 Colt that has been fed a steady diet of heavy loads for some time now. So far so good.....

The mini mount and an Eotech MRDS has been great on a SBH with 300 gr cast bullets at 1250 fps.

I like the JPoint reflex sight. They have a mount that fits all Ruger revolvers, both single and double action.

I tested a JPoint and it didn't hold up well. I like the clean mount, though.

I had a JPoint mounted on a SRH .454 which took a lot of rounds without problem. I've also had another one mounted on the slide of a Glock 34 which has lasted countless thousand rounds. Its a sight I like a lot.
That being said I know there are some people who have experience problems. By the same token, I'm unaware of any brand/type of sight that hasn't had some failures (including iron sights).

I've had an Optima2000 (predecessor to the JPoint) riding the slide of a 1911 for I don't know how many rounds and it is running strong. Also had one on my Bisley 45 Colt for a number of years holding up to a lot of max H110 loads, until I swapped it for a 1x scope. They work well, and yes not every sight is infallible.

For what it is worth, I had a FF3 on my 41 Magnum and it lasted 50 rounds.

My next move will be the trijicon RMR dual illuminated sight, I believe.

I really like my SeeAll Nite. There's a little learning curve with it, but the tritium makes it usable 24/7. Were I to buy another revolver, it's the sight I'll install ... hence my interest in the new Weigand Mount.

My JPoint has been on my custom 510 GNR (shortened 500 Linebaugh) for 4 years and I've never had an issue. I shoot 385 grain LBT's at 1300 fps.
I also have a JPoint on a Glock 20SF that has absorbed close to 1000 rounds with no problems. If you buy enough stuff, you'll eventually get a lemon from any manufacturer.