It's quite a distinct pleasure to read Le Carré, but it's certainly not fiction for the Adderall era. The pacing is far different from most modern fiction: there's no cliffhanger or plot twist every ten pages to hold the reader's attention. Instead, his stories take their time and gradually envelop the reader.
Single and Single has an intricate plot, with several characters and threads that the author gradually weaves together, and then, over a bare few pages at the end, accelerates into a rapid resolution. It's not his best novel, however, and if you're looking for peak Le Carré try his earlier novels Our Game and Tinker Tailor Soldier Spy, both excellent.