Panniers or rack top bag?

I can’t recommend a rack and
I can’t recommend a rack and pannier enough. It’s so much nicer than using a rucksack. I ride just with one pannier, it’s enough space and I don’t suffer from any balance or space problems.

A lot depends on what you are
A lot depends on what you are planning to carry, but I’d say panniers all the way.

Plenty of space for the unplanned trip on the way home or to stuff a jersey or raincoat in without having to faff about rolling it ultratight to fit into a small space.

Make sure you buy seperable ones where you can use just one, and not the el-cheapo all-in-one wardrobe sized ones from the likes of Argos.

Unless you buy Ortleib or manage to find the Aldi rip offs, buy some rubble sacks or rucksack liners to use as inner bags to keep everything dry for that commute when it’s chucking it down..

I use a pannier most of the
I use a pannier most of the time. if you’re going to work and back and planning to take it inside then it’s the most versatile solution, i find. you can stick a bunch of shopping in there too. i have a carradice saddle bag too which i’d use in preference if i was doing a long ride and i knew what i was carrying. but panniers allow you to shift stuff you didn’t allow for a lot easier.

Panniers all the way and
Panniers all the way and stacks of choice out there (in comparison to rack bags which are pretty limited in their capacity). They don’t slow you down either and you avoid the rucksack sweaty back. In support of rack/saddle bags, I did spy a Carradice bag the other day. Quite smart and a bit ‘retro’, but probably not cheap.