1. I will pay privately for a C/L fill in order to have 1 or 2 month reserve in case there is a shortage, like the the MYLAN shortage recently caused by the hurricane in puerto rico. 25/250 costs just a few dollars more than 25/100 C/L. It has less carbidopa, so if you use it you might have to adjust the dosage.
2. It splits into 125mg and 62.5mg pieces which gives you more options if you take it with 25/100 C/L. With the 2 strengths, you can have 50mg, 62.5mg, 100mg, 112.5mg, 125mg, 162.5mg, 175mg, 187.5mg, 200mg, 225mg, 250mg, 262.5mg doses.
3. if you are partial to one brand, you might be able to get the 25/250 if the 25/100 is unavailable.