I suspect the issues come from different climates. When my system was converted in the Burb, the condenser was not changed initially. It would get nice and cold while driving down the highway, that would mean constant air flow over the condenser, but once in stop and go traffic of in the city with lights and such, it would warm up and feel like a swamp/evaporative cooler.
I would tend to thing the hotter air in the desert climates makes it harder to keep the condenser cooler than it would in the midwest areas that "usually" don't see anything above 100*
I had even tried adding extra cooling fans, it helped minimally.
There was one time with my old Monte Carlo that was converted that it actually got cold too, but it's when the clutch on the engine cooling fan had froze/locked up. It was an 8 blade fan I found somewhere and when the clutch locked up, it kept EVERYTHING cool, pulled in a ton of air, of course it sucked the engine down on power too though.
If you're converting, I would highly suggest swapping out the condenser to get the most out of the system if you're going to do the conversion, do it right the first time so you're not fighting with it like I did.
I eventually bought the condenser, which was not too badly priced at around $125 or so when I got it, but by then, all the heating up of the compressor from inadequate cooling due to a condenser not designed to run with 134a had taken it's toll on the compressor and when I finally got to installing the freon, the compressor finally quit.
I haven't messed with it since and just dealt with the heat with plenty of water and kept my driving in summer months to a minimal.
Get the new seals, get the new orifice tube, get the condenser, vac the system down real good to eliminate any moisture, oil it and fill it.