Echo the majority of comments in this thread. It's the same reason I am a monarchist.
However the Lords can be used as a political tool, Cameron for example wants to pack the Lords "to reflect the situation in the Commons", which completely misses the point and (wilfully) misunderstands the reason for the disparity: there are many independents and Lib Dems in the Lords, so that Tory (and all other) Lords are in a minority, for precisely the reasons discussed ITT.
I don't know enough about it to say how the Lords should be reformed, in terms of the elevation of ex-ministers, party donors, hereditary peers and bishops. Instinctively I want to remove all elements of Commons party allegiance from the Lords, but that may obfuscate things even more with Lords acting with party allegiance just not declaring it.
I think it's unequivocal that the size of the House ought to be reduced though. The problem is if you want to make party political appointments you can't exactly do it by removing the privileges of those already there, you can only add more people to it. My first thought is to give Lords a reasonably long time limit, such as 20 years, after which they must step down, but to be fair this is basically what life peerages are, except with unpredictability built in (which is good).
Also unequivocal I think is that there should be more scrutiny and popular coverage of what they get up to. This is not forthcoming probably because they don't have the power to do much more than delay bills and because they are not elected so no special interest group stands to gain from informing the populace of the good and/or bad things they say and do. I think more coverage would be fantastic for developing independence of thought in the national conversation, however, as opposed to partisanship (and turning the PM into a president) which seems to be getting worse.