A matter of personal choice I guess, jambop, and what suits your growing conditions and style.
I don’t grow determinants as my space better suits cordon grown plants.
I have always grown it as a bush because space is not limiting but I think this is why people try it as a cordon because of use of space like yourself. Premier a seeds list it as semi determinate... what does that mean?
edit out of curiosity I just went to PS website and looked at their listing for Roma and they have changed it but the growing tips they give are really for a cordon type plant. I find their tips to be a bit strange really. I also do not regard them as the king... San Marzano will always be the king
Tomato Roma Vf
Tomato Roma Vf. The king of Italian tomatoes, most commonly used for sauces and canning, but equally delicious in summer salads. It is the ultimate mid season Tomato, perfect flavour, perfect pear shaped 3″ fruits, all beautifully red. Plants grow on vigorous determinate vines producing a heavy mid-season crop. Fusarium and Verticilium resistant.
Cultivation advice Tomato Roma Vf
Sow in spring 1/16 inch deep. Germination takes around 6-14 days at 65-75F.
Transplant the seedlings when large enough to handle into 3 inch pots. Grow on under cooler conditions and when about 8 inches tall, either plant in their growing position in the greenhouse or gradually acclimatise them to outdoor conditions and plant out 18 inches apart in a warm and sunny spot in moist, fertile well drained soil and keep watered.
Provide support and tie in regularly. Remove side shoots and restrict the plant to one main stem. In late summer remove the growing tip to hasten ripening.