I use a lot of 35mm TRI X and switched from Rodinal to XTOL some time ago. Each developer works well with TRI X but I prefer my TRI X in neat XTOL. I usually dev for 7.5 mins @ 20C (rated at 400 ISO) and only do six films through one litre then throw it away. Great negs and easy to print. Interestly HP5 + also goes well in XTOL at 8 mins. I mainly keep Rodinal for the Konica infraded and Kodak infrared films.
If any one has experiece / times for Neopan 400 in XTOL I would be interested to hear about these.
Summary: XTOL / Rodinal are both excellent developers but after quite a bit of use of each I prefer XTOL for my work (mainly landscapes).
Give them a go - Rodinal is cheap and will last for ages.