Yes, their main area is Padd-Didcot stoppers plus Padd-Newbury & the Newbury-Reading shuttle. On the mainline, I believe they also do:
1A63 0700 Swindon-Padd
1U06 0813 Padd-Bristol PW
1L13 1024 Bristol PW-Padd
1C41 0915 Padd-Swindon
1A66 1025 Swindon-Padd
1C43 1013 Padd-Swindon
1A67 1146...