Seventh-day Adventists rely on the Bible heavily. So if asked what is our understanding and use of the gifts of the Spirit, then a verse such as 1 Corinthians 12:7-10 sums it well.
1 Corinthians 12:7-11: But the manifestation of the Spirit is given to every man to profit withal. For to one is given by the Spirit the word of wisdom; to another the word of knowledge by the same Spirit; To another faith by the same Spirit; to another the gifts of healing by the same Spirit; To another the working of miracles; to another prophecy; to another discerning of spirits; to another divers kinds of tongues; to another the interpretation of tongues: But all these worketh that one and the selfsame Spirit, dividing to every man severally as he will.
The gifts of the Spirit can include wisdom, knowledge, faith, healing, miracles, prophecy, discerning of spirits, tongues and interruption of tongues. Basically any talent that is good, because it is from above, by grace. These gifts however amount to nothing if it is not tempered by love (1 Corinthians 13:13), the greatest gift of all. For we know that "knowledge puffs up, but love edifies" (1 Corinthians 8:1).
1 Corinthians 13:13 And now abideth faith, hope, charity, these three; but the greatest of these is charity.
Unlike the early church, however, God's church today displays a lessor degree the gifts manifested by early Christians. This in part is because we are living in a different period where faith without sight is expected, but also because we have grown soft, having no persecution, and lack the faith of those early Christians. However, this does not mean that these gifts are no longer accessible by the church body today. On contrary, the Bible says
"And it shall come to pass in the last days, saith God, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams" (Acts 2:17).
One unique element about the Seventh-day Adventist church is our belief in the existence of the gift of prophecy today, this is what we often refer to as the spirit of prophecy. In Revelation, it is explained that "the testimony of Jesus is the spirit of prophecy" (Revelation 19:10). It is also shown that it is God's people "who keep the commandments of God and have the testimony of Jesus" (Revelation 12:17). Therefore the spirit of prophecy is very much alive and is a distinguishing feature. Adventists are one of the few denominations that claim to have a clear and systematic understanding of Daniel and Revelation based on history and Biblical supporting texts. Indeed these were once closed books, but it is also written, "many shall run to and fro and knowledge shall increase" (Daniel 12:4). We also believe that Ellen White had the spirit of prophecy and that the visions she claimed to have received from God were authentic. For when we test the contents of her testimony we find that it upholds the Bible, points clearly and only to Jesus, and encourages the reader to pursue a deeper relationship with God and understanding of His word. For those not familiar with her works I recommend the Desire of Ages, it is an excellent rendition of Jesus' life, enjoyed by Adventists and non-adventist Christians alike. Her descriptions of Jesus' infinite sacrifice and love is a testimony of her understanding and humble personal relationship with God.
Updated section for revised scope in the question
Spiritual gifts are available to any sincere follower of God, all who are partakers of divine nature by grace through the Holy Spirit. The only condition according to Jesus is: "If any man will come after me, let him deny himself, and take up his cross daily, and follow me." (Luke 9:23). Spiritual gifts are for the benefit of both the person in possession of the gift and those who bear witness.
Spiritual gifts still exist in the Church but are less miraculous in nature today, for God has called us to walk in faith rather than sight. In the last days, it is Satan who will be permitted to perform great miracles and lying wonders (2 Thess 2:9, Rev 13:14), even bring "fire from the sky" (Rev 13:13). Instead, the Holy Spirit and faith are required to discern those in possession of true spiritual gifts. The spirit of prophecy, knowledge, wisdom, faith, healing, spiritual discernment, and love will be in existence on the earth until the very last day. In addition, it will be aided further by the "latter rain" (Joel 2:23, James 5:7), a powerful outpouring of the Holy Spirit before the time of trouble and the last plagues.