I really like m y .243. I do have a 22-250 and a .270 WSM as well for something on either side of the power spectrum, but the .243 is real sweet. Without a doubt, it is the easiest of all my rifles to come up with an accurate load for a desired bullet weight. I have eventually come up with several good loads for each of my rifles, but it takes a lot more work to find an accurate combination for a 7 mm mag than it does a .243.
Originally, I loaded up 100 gr Hornadys in the .243 to use for deer. No problem. I got great groups using 3 different powders. Then I tried 75 gr Sierra HP bullets. I tried just one powder and found the right charge weight very quickly to turn it into a super accurate and fast varmint round. Lately though, I have been working up loads for an 87 gr bullet. Once again, it was easy to find a powder that gives great groups. I have found really nice groups in all weights using H4350, W780, RL-22, and Big Game powders, but my all time favorite powder for this cartridge is Ramshot Hunter.
Everybody needs at least one .243 just for fun.