According to forum posts, Top Rent a Car is frequently mentioned as a reliable option, having a good reputation and newer vehicles. However, some travelers have had negative experiences, citing issues like unfair charges. Sikon/Smart Rent a Car also receives praise for its low rates, good condition vehicles, and excellent customer service.

For many users, renting from companies that offer dual-fuel vehicles, such as those running on LPG, is beneficial due to the lower cost of LPG compared to petrol. This option was highlighted by a user who rented from Sikon/Smart Rent a Car.

Some travelers said that the booking processes with these companies are straightforward, often involving a simple online form or direct contact via email or WhatsApp. Positive remarks were also made about the clarity of communication and the helpfulness of the staff during the rental process.

According to forum posts, travelers have multiple public transport options from Sofia Airport to the city center. The metro from Terminal 2 is a popular choice, with a direct line (M4) to the city center, connecting to other lines at Serdika Station. Additionally, public buses are available from Terminal 1, providing another cost-effective route into the city.

Some travelers have discussed using official taxis like OK Taxi for a more direct route to their destination. However, there is a caution against using the Ryanair shuttle bus due to reliability concerns mentioned by users.

Travelers have called out the ease of planning journeys using the sofiatraffic.bg website, which provides detailed information on routes and schedules for both buses and the metro, ensuring visitors can find the best option suited to their schedule and location in Sofia.

Some travelers recommended a free walking tour starting in front of the Courthouse in Sofia, which is highly appreciated for its affordability and informative content. This offers a budget-friendly way to cover cultural sightseeing in the city center.

For those interested in outdoor activities, hiking in Vitosha Mountain is popular. It’s easily accessible via public transportation like bus or tram, and offers scenic trails suitable for a day's adventure. Additionally, a day trip to Koprivshtitsa provides opportunities to experience traditional Bulgarian culture and architecture, with cobblestone streets and historic homes to explore.

According to forum posts, spending time in the central parts of Sofia allows visitors to enjoy local cuisine, museums, and pedestrian-friendly streets. For a relaxed day, exploring local markets and parks is also recommended.

For a more leisurely experience, some users have suggested spending a day at a spa or attending local events and festivals, which can provide a relaxing and culturally enriching wrap-up to a short stay in Sofia.