You got tired, coz the way you configured your HTPC might not be optimal, 15 min to start a PC, there...there!!! that itself tells why you got tired. Even the lamest, tired and slow to the core PC (of last 10 years) does not take...maybe more then 3-5 min to start. I will throw all my PCs if anyone of it takes more than 5 sec to boot, ...8-10 at the most. With openELEC .... definitely not more than 5...anyway ...
yes, PC does not take more than 3-5 minutes to boot, but thats just like switching on a player, next is loading a disc, then anyDVD will scan the disc which sometimes takes a lot of time, then start a player, then the disc will be loaded into the player which may ask you to check internet connection for BD+ codes, then many disc menu can only be handled with keyboard and mouse does not respond to the menu, many a times full disc menu does not load automatically
now I have a few observations
1.majority of HTPC with BD drives use a series of softwares such as anyDVD,powerDVD,Bluray region tray etc., how someone is supposed to get them? in India the answer is so easy, get the pirated ones, I do not really like to use pirated softwares when spending so much for BDs
2.if one uses the HTPC for stereo (audio), now you have to change sound devices (sound card to HDMI), one of the major flaws with HTPC is there is no cost effective way of getting a second small display, for playing music switching on the TV is meaningless
there are others.....
But there are positive points as well, for instance ripping a BD to a MKV/MP4 is a fun, but again one needs softwares,by the way I am really happy to use makemkv+handbrake+mkvmerge in ubuntu
for playing a media file(jpg,mkv,mp4,avi,mpg...) a full HD TV is sufficient, its a matter of few seconds, building a HTPC needs time,patience,learning and money while for playing media files and BD/DVD discs a decent BD player is cheap,fast and plug and play option which is hard to beat, I strongly doubt how many HTPC users actually use it for functions which can not be performed elsewhere, just for playing media files keeping a PC and obviously an UPS has lost its significance
But if one makes the HTPC to perform audio playback,media player,DVD/BD playback,storage,encoding and transcoding,recording through TV tuner card,internet media streaming,high quality upscaling then it really justifies the investment
my two cents only