How should you go about choosing a commercial solicitor?
At a minimum, you should be looking for someone who is expert in the relevant area of law, works efficiently, avoids errors, is able to communicate effectively with everyone else involved in the matter and produces documents and performs other work promptly and in accordance with any agreed or imposed timetable.
As with any professional service, personal recommendations are valuable. Recommendations from in-house lawyers are particularly valuable, at least where the in-house lawyer has the ability to assess the technical expertise of the solicitor.
A solicitor's expertise will not necessarily be proportional to his or her fees. There are plenty of expensively incompetent commercial solicitors, and quite a few relatively inexpensive experts. That said, you should be able to place a measure of trust in most large and well-known firms. And those are the firms with the highest charge-out rates. Except in the case of large-scale litigation and transactional work, most legal services are provided by an individual lawyer or small team working under an individual lawyer.
The reputation of the individual may therefore be more important than the reputation of the firm. It will usually be harder to find information about an individual lawyer than a firm. The principal directories of the legal profession - such as Chambers and Partners and the Legal 500 - are worth consulting, although they have limited information about individual lawyers and mostly cover the bigger and better-known firms. You may also be able to glean relevant information from social media such as LinkedIn.